Time Tunnels

The other major plot device are the Tunnels of Time or Time Tunnels. These are caves that will propel a group of people to any time or place. There are a great many of these. There is a lot of arguments regarding the source and purpose of these fantastic places among the minority who believe they exist. The vast majority of the population of all times and cultures is that they do not exist.

Here's how the Time Tunnels work.
There are none above ground and are always found in natural caverns although many caverns have been extensively modified by religious and technological parties. Some folks worship them, some are trying to discover their secrets, some guard them as tribal "JuJu".
They are very, very high tech. The mechanism exists outside of time and can't be touched in any way. They can malfunction, but have a self correcting mechanism that will fix problems given enough time (it may take millenniums).
When a party enters into an Time Tunnel area underground, the Artificial Intelligence programs become active. Sensors determine the number, race, armaments and so on. Defensive systems become active although there is no outward sign. The laser blasters are hidden in the rock and require a spot at a DC 32 to find. The visible part looks like a tiny round piece of glass. Laser BAB 20, slash damage 3d8
The room is always large and have room for from 6 to 20 (depending on the size) tunnels.

The party will ask what the tunnels are for and the AI will tell them how it works.
If they leave the Area, they are not a threat. If they stay they will die. The AI has no control over the times available. Questions about who does get the "I am not authorized ". The AI doesn't even know what time or place they lead to. This is another security feature. Only those who have a way of knowing where they go on their own have a real use for these devices!

If this was the only thing going on with the Time Tunnels it would be really stupid. How can you talk any sensible party into going on a random journey more than once?
Although the technology of the Time Tunnels is far beyond anything this world will ever be capable of (and is unique in the known galaxy of Traveller), attempts to find a practical use for it have been going on since the first civilization. Only in the future of the party has some advances in the technology been discovered.

Here is one possible way the characters could be introduced to the situation.

Somehow, the party is directed to a ancient site buried in the mountains. The legends of the place go far back in time and it is assumed that the clues lead to either great treasure of possible to great knowledge. They are hired (or decided to follow the leads themselves) and delve into the mountain where they find some rocky tunnels. They lead to a chamber of rock that looks like a dead end.
When the party has gathered in a spot where all the party is within the area that will be cut off, a force field will appear. A woman's voice will say
"Security protocols enabled. Time Tunnel Alice awaiting instructions. "
The Tunnels will then come on and display whatever images the DM wants. This is a chance to provide previews or imagination candy to the party. Mose of the scenes won't be interesting. Many of the tunnels end in areas that are completely uninhabited at the time the tunnel ends. Some may provide hints to adventurers the DM would like to run. How to convince the party to choose the tunnel that leads to the adventure is left up to the DM.

The AI will not be really helpful in terms of game information. There is a strict embargo about questions regarding the past or the future and will be answered with "I am not authorized to provide that information unless the Security Protocol Alpha 20 is invoked.". Shortened this becomes "I am not authorized to answer".
The party will soon realize that they are in a trap. Someone will ask someone what the wall of force is for. The AI says
"It is part of the system security. Unauthorized exit from this area is strictly forbidden. Under the Time law Chapter 3, section 48, paragraph 231 entry into a Time facility is strictly forbidden. AI systems are authorized to euthanize all animals remaining in the area for more than 48 time standard hours. You have been in the area for 63 minutes and have 46.9 hours remaining."

Obviously, this is a Hobbes choice. Eventually the group will decide to pass into one of the tunnels. When they do, the will encounter the living beings that are the "ghosts in the machine".

When the characters decide to chance one of the tunnels, they will experience what seems to be an eternity of darkness. When at last the darkness clears, they will be presented with a wholly unexpected scene. They will come out of their blackness in a Hiver nest! The Hivers are very intelligent monsters from the Travaller universe. They are the team of investigators who were sent from the far future to discover the secrets of the only time travelling facility in the galaxy. Their objective is to discover as much as possible about the technology used to create the Time Tunnels in hope they can be adapted for use on the Hiver home planet to create a utopian environment there.

Although they have gained more knowledge of the Time Tunnels than any other race, they will admit to being infants in the advancement.

They have grabbed the party "from the buffers" and materialized them in the place where they are which is "out of time" i.e. not connected to the current time line of the system. They will explain the following to the party:

"We are not inimitable to your race although we do not pretend to understand your psychology. The fact that it appears you have developed what appears to be a technology that even outstrips that of the Ancients is proof either of your superior intellect or of your discovery and understanding of their technology. This is far exceeding the accomplishment of other races in this area."

This being said, they admit they are still somewhat interlopers in the Time Tunnels which they invariably refer to as "the project":

They can use the buffers to capture parties and inject them into specific time streams after those persons have undergone an extended debriefing from the3 Hivers.
There are only 3 of them, but they seem to think this is enough to direct the groups seeking to guide the civilizations of this planets to 2 ends.

End 1, the Hivers want to create a time traveling utopia for their home planet. This will require a obviously clear explanation of all factors around the time project, how it was implemented and how that may be extrapolated to the current "experiment".
End 2. To further end 1, they believe that it may be that the time device would not have been created without their interception.;  To their mind there is nothing unusual in participating in a system that impacts a result without clear knowledge of the intermediate outcome. 

The bottom line is that they pay groups of people real money to perform single tasks at their direction.

The simplest task is the placement of an "Obelisk". This is most often the first task they are sent out on and is referred to in Time Central as "a box job". This is a delivery service where one of the Hiver technology teaching machines is placed in an area frequented by carefully targeted individuals. Unfortunately, while the target name and time is clearly known, the physical location of that person is not know exactly. This sometimes requires the party to find him and then drop the obelisk off.

The obelisks come in many sizes but their dimensions are always exactly the same they are 1x3x7 in proportion. Some are 1' thick, 3' wide and 7' high. These are teaching machines. When a person comes within 3' of the object, the mechanism starts. First, it paralyzes the person and then begins a process of determining the mental engrams which it uses to optimize the imprinting using natural idiom and cultural reference. After a few minutes, the person walks away with no memory of anything except sometimes finding a strange shaped object. However, the new information is there when they want it. Usually it will take years for the person to "stumble on" the imparted information which makes it look like independent inspiration and hide the participation of the hivers.

The obelisks are constructed of both hardware and wetware and both are programmed to disassociate themselves when their job is complete.

The black obelisk boxes are invisible to the tunnel scanning mechanism as long as there aren't to many going through and as long as they are small. Any box larger or any number greater than 3 boxes at a time will trigger the security system and they will be "deleted".

Another common task is called "a drop". It consists of taking something from one point in time to another. Only the Hivers know what is inside the containers and only they can open them without setting off the booby trap that destroys the contents of the box completely. They are guarded by a genetic lock keyed to one of the hivers. The group is sent to a spot and instructed where to get the box and bring it back to Time Central. Often they are then instructed to take another box (that looks identical) to a different time.


When the party is brought before the Hivers, they will be given a choice.
The hivers will send them on their way to where ever they were bound for with all the food and drink they can carry.
They will send them back to the place they came from.
They can stay on as hosts or
They can do a job for the project. The group is given a task to perform. They are prepared for the time destination. They are given the location of the closest Time Tunnel besides the one they come through. They are sent to a Time Tunnel that is as close to the objective as possible. When the task is complete, whether it was successful or not, they return to the Time Tunnel and are brought back to Time Central. If they successfully perform the task, they will be given a lot of money in what ever format is best for the time they came from and send them back where they came from. This is always a portable form of wealth ranging from an anonymous numbered bank account to untraceable diamonds or a small, valuable work of art. The amount should always be enough to support each of the players for the rest of their lives. In D&D terms this would be something like 50Kgp worth of mixed gems or for modern day terms 1/2 a million dollars.

However, the Time Tunnels have another security system. It is selective amnesia. To prevent cross-time contamination, the Time Tunnel device will erase the memory of experiences or knowledge that might be damaging to the timeline that is their destination. This editing occurs between transport from Time Central to the destination. This knowledge may return if the person returns to a time where the information is no longer dangerous, but may forever deleted. As long as the players stay in Time Central they have access to all their memories. This is a large part of the attraction to the hosts who enjoy their memories of past adventures.

So part of the deal is that they may have edited memories of what they do in the field when they return to their own time.

The party will need to know where they are at any time. In order to accurately find the caches and their locations of the objectives, they will have to have fairly accurate locators.
It is not possible to transport a physical object through the tunnel without using a box, so wetware technology is used to embed a location system based on the location ability of birds was developed. This requires surgery to embed the modification into the bodies of 2 party members. This enables those people to determine their longitude and latitude down to minutes at any time.

Naturally the Hivers will have a contingent of human is their large out of time facility. They refer to themselves as the "hosts". This will include members of every sentient race and are all Voluntaries. Most of them are retired operatives. They will great the party, make them comfortable, answer most of their questions and prepare them for the introduction to the Hivers.

Time Travel
The planet is unique. It is the only planet in the known galaxy that has "Time Tunnels". These aren't really tunnels although most of them are contained in underground areas. These allow groups of people to travel through time and space, but only on the planet. No one knows who made them or why. The party will stumble upon one at some time.
Travel through time is not under the direct control of the party. In fact, there is no one who can really control them. There is however a sort of "mouse in the walls" that can control them somewhat.
An alien race from the far future has found a way to use the Time Tunnels to create a space out of time called Time Central where they live and study the Time Tunnels with the aim of duplicating them on their home planet. When someone uses the Time Tunnel, these aliens have the ability to "read the buffers" and pull travellers into this non-time then redirect them to an approximate time and space of their choosing. They have created a cadre of operatives that perform specific tasks for them all with the aim of discovering the means of making their own time tunnel.
These tasks can be giving something to a person, receiving something and  taking it back to Time Central, create a cache of gear for another group and so on.
If the party agrees, the party will be sent out on a job in some other time and place. They will then be brought back and rewarded with the currency usable in their home time. The party will then be sent back home close to the place and time when they left carrying a fortune.

The Time Tunnel has a built in security system designed to protect Time from anomalies. This take 3 main forms.
Any living creature that is a threat to the destination time is disintegrated. Diseases, parasites and the like are eliminated on transfer to or from a spot.
The TT does not transport non-living material. You arrive at your destination naked even if you left clothed. Anything non-living inside a character is destroyed and gives the person a debilitating stomach ache.
The TT edits memory. If a skill, feat or personal memory is though to be dangerous by the Artificial Intelligence that runs the system, they will be eliminated when the person is transported to a spot in time/space where they might cause an problem.
While in Time Central the characters retain all their memories.
The Aliens that run Time Central have studied the memory effect and have achieved a major discovery. Unfortunately it only works on humans, but they are very proud of it none the less. They have discovered how to control human memories.
When a party is given a task, I will provide a set of skills, feats and other class related traits that will be useful. The players will then swap them for their current skills, feats and so on. In essence, only the characters ability scores and senses will remain the same on the new adventure. Players will have the option of creating a completely different character or keeping elements of their current characters. The characters will then go into the adventure with a custom created character that fits into the new time period.
Equipment needed by the group will be provided either by a cache (items placed near a TT exit by a 3rd party) or through a contact that lives nearby.
Magic works only if the memories of how it works are retained.
Technology only works at the appropriate destination time and objects can not be transported through time. There are special cases to this rule.
Psionics requires a "wet ware" addition to a character. This organic modification is seen as a parasite and destroyed unless the character is going to a time where psi is used already

The facility, commonly called "Time Central" to the hosts, is about the size of a city block. 1/4 of this is occupied by the mysterious machines that create this space out of time and house the great computers that do the vast computational tasks necessary for the analysis of Time Tunnel sensors and buffer capture and insertion.

Their proof that everything is going well is that the Time Tunnels continue to work. This is an almost tautological argument from a human point of view, but they are convinced this is an acceptable risk for their meddling.

When they find a party with the AI Evaluation of their physical and mental profile indicating them  to be a useful group of "Agents",  they will make an offer to that group. They may not disclose all the permanent info to the party, but they not mislead the group in any way.

There are ranks among those working for the project.
Agents - low level people. Level 1 through 5
Operatives - trusted Agents with multiple tasks successfully performed. Levels 6 through
Trouble Shooters - High level operatives with considerable autonomy.

The Hivers are neutral as regarding the inhabitants of the planet as they only want the technology of the Time Tunnels. They do help humanity, but only to force them toward technology as the solution to their research.