I emailed Roger and Mark before the last session to tell them what was likely to happen. For interest, here's what I sent to Mark:
EMAIL TO MARK : At some point in the next (or possibly the one after next) session, the unfortunate colonel is going to be literally turned inside out by an experimental machine of the Great Race of Yith (you'd figured that bit out, I suspect). Simoultaneously, the poor colonel's mind will be transferred to the bodies the Great Race at currently occupying (which happens to be a swarm of flying insects, each with a controlling hive mind - each Yithian comprises 1000-4000 of them).
Here's the stinger - the poor colonel will never return to his body. He'll find himself occupying 3000 beetles in a cage suspended over a dark pit, and his tenuous grasp on sanity will be severed forever. I'll give you a moment to get over the loss of this treasured character.
Right, pull yourself together, man. The colonel's body fares rather better than his mind, being repaired some minutes later, but from this point on he is instead controlled by a Yithian. This particular Yithian has occupied humans before and won't make basic mistakes - any disorientation will hopefully be out down to the horrific experience the colonel has just gone through. The Yithians are also telepathic in this time period and will have gleaned most surface thoughts from the colonel, so he will know most things the colonel should now.
Here's why - the Yithians have a mission. The end of time is inaccessible to them - they can travel into other consciousnesses, but no such consciousness exists at the end of the universe, and they want to find out what happens. The current competing theories are
1 - time is circular. The future eventually circles back around to the current point, and so on, for ever. In this scenario, there is no free will.
2 - time is cyclical. Time cycles back to a similar but not identical point - free will exists.
These humans are going to help them find out which is correct. The poor saps will be tricked into thinking they can escape their current predicament in a time machine. Instead this machine will enslave them until the end of this universe (at a greatly accelerated rate) and cross the barrier to find out what is on the other side. The plan is to deposit the beings at the same or very near point in the new timeline and see what happens. The great race don't want to try this themselves until they have tested it on lesser races.
Here is you goal - the very second that you can confirm (or not) that you have arrived on Earth, and the party has exited the machine safely and without dying, they become expendable. Your task is to immediately dispose of all of them to prevent any warnings reaching any authorities that may have the slightest chance if upsetting the plans of the Great Race (assuming they still exist in this timeline).
And here's what I sent to Roger:
EMAIL TO ROGER: As you may have guessed already, you aren't John Hanrahan. That is to say, you're not the John Hanrahan that started the adventure. When you encountered yourself in that alley, you were killed... or incapacitated (see later) and taken over by the... shall we say previous?... Mr Hanrahan.
This isn't the first time. You (the attacker Hanrahan) have been through this sequence of events before, exactly as they are occurring now, and you know where they are going to lead... unless you do something to stop them. Here's what happened to you - you experienced the adventure exactly as you already have, with the exception of the potentially fatal encounter in an alley. The gate you have just been pushed through leads to Earth... an Earth millions of years in the future to the one you know. Good news: no capitalism, and no imperialism. Bad news: no people. You were the only humans alive on the planet, and you were put through tests by (as you may have already guessed) The Great Race of Yith, currently in their new bodies. Each of them occupies a swarm of 1000-4000 beetle-like creatures now. These beings are able to transfer their minds into other bodies.... you have no idea what their ultimate plan was, because you managed to escape, aided by the mind of a Great War pilot, now trapped in a swarm. He stunned some of the other swarms, and guided you to your escape in what Mr Wells (the imperialist dog!) would describe as 'a time machine'.
However, something seemed to go wrong. Instead of transporting you back in time, it catapulted you forward, right to the end of time. You watched the Universe end.
And then you watched it begin again. You saw stars form, and galaxies, and (eventually) The Earth. As time passed, you say human civilisation begin again, and soon (well, subjectively soon) the vessel arrived in England, in the 1920s. Curious, your party left the machine, and it's at that point that things went very badly wrong. These beings can control minds. At some point, they began controlling the mind of the colonel. As soon as it was clear that the vessel had the survived the trip, the colonel/Yithian made his move. Within a few moments, the rest of the party was dead, and you barely escaped with your life. Miraculously, you managed to defeat him, and take his weapon, but by then it was too late. Everyone else was dead.
That's when you realised the date - it was the night of the lecture. A desperate plan struck you - was this world similar enough that the same events were about to take place? If so, you had a second chance! This time round, you could prevent the colonel's attack, and save the rest of the party! There was just one obstacle... you. You needed to be the Hanrahan that found that vessel, and so you beckoned yourself into an alley and... well, this part is up to you. Whatever you did, it incapacitated him/you in such a way that he didn't appear for the rest of the adventure. The simplest way is, of course, to kill him/yourself... but if you can think of a preferable way of doing it, you're welcome to tell me. Whatever you did, it worked, and you lived the adventure again.
You realised that you had to live the adventure exactly as it had been lived, up to the point of the colonel's attack. Why? Because if you never went to the Moon, it's possible that the power of those beings may end up in the hands of the British Government, and Marx only knows what horrors they could inflict upon the oppressed masses with such power at their disposal. Secondly, if you went along to the moon, and were captured as before, but killed the colonel before you entered the time machine, then the Yithians would simply possess another one of you, and you would have no idea who or how they would attack. You don't know when the colonel was possessed (although you have an idea), but you -do- know what he does. Anything else is an unknown quantity. Your plan depends on your knowledge of the past/future. You need to wait until the colonel makes his move (again).
A third point... and one you've tried not to think about very hard. If all this happened in the previous universe, does that mean that time is perfectly circular? Does it just go round and round again? And, if that is the case, is there even such a thing as free will? Can you even, come to think of it, change anything at all, or are you just a puppet (albeit a puppet which can now see the strings)? You have attempted to test this... a few times you've tried to walk in a different direction, or say something slightly different to the things you said before, but... it's curious. You feel... powerfully reluctant to actually do it when it comes down to it. Even when you have managed it, it seems... well, it seems that the moment you have done it, you remember it happening before anyway. It's almost as if you are misremembering what actually happened until you do it, and then realise that you just did the same as before anyway. Maybe... maybe your memories change when you change time? Maybe. A person could go crazy thinking about it, but you don't have that luxury. You have a job to do.
Here's how it's going to work in play... I don't actually know what the colonel is going to do, but he is briefed to destroy the party as soon as he can after exiting the machine. He's going to make his first move, and it's likely to be successful, owing to the surprise element, and the fact that he has been supplied with a highly lethal laser pistol. Whatever he does, I will let him do, and then explain... 'At least, that's what happened the first time...'. This time around, you know it's coming, and we'll run the round again, only with you describing how you counter that move. After that, Mr Hanrahan, you are on your own, and the fate of the party lies in your hands.