As they work more for their employers, they are given more freedom between missions and their memories are not blocked. As they are prepped for their next mission, it is clear they have extra things to do. They become aware that their employers are trying to align their arrival to meet “The Traveller”. They give Frederick an extra time bracelet to be given to “The Traveller” once he is contacted, but give no more information.
Thaddius and Frederick arrive in an underground tunnel. Maria is not with them on this mission. It is dark. After turning on their torches, Frederick recognises that they appear to be in the London Underground – in one of the train tunnels!
They decide to head in one direction and they see and hear something strange ahead. The find the tunnel is blocked with undulating goo-web that Thaddius remembers from the cave in Tibet. They back away as the web seems to bulge and then strange figure stumbles out, covered in goo. It is vaguely humanoid, but large with a huge circular “head”.
The time travellers flee back in the other direction. Eventually, they encounter a station with a platform – Moorgate. A ticket dropped on the floor reveals it is February 1967. They attempt the exit the Underground via the station, but discover that shutters have been pulled down and some sort of barricade erected behind them – there is no way to get out.
Thaddius examines his psychic paper for clues. He sees the figure they saw stumble out of the web again, the one with the huge head. No wait – it’s the helmet of a spacesuit and there is a man inside.
They decide to go back down the tunnel towards the web to examine to find this person. After retracing their steps, they encounter the figure again. It is stumbling around apparently blind, still covered in the web-goo substance. They try to communicate but it just seems to move towards their voices.
Frederick grabs a nearby fire hose and uses it to clean off the web-goo from the spacesuit. They can vaguely make out a man inside, through the glass helmet. They help him remove the helmet and talk to him. He appears to be American, with a southern accent. He rambles in-coherently about zombies and aliens, saying his name is Karl.
They decide not to stay here and help Karl back to Moorgate station. When they arrive, they see that some boxes of TNT have been placed on the platform since they were last here, with a cable going off back in the tunnel direction they have not explored yet.
As they begin examining the boxes, three soldiers emerge from the darkness, carrying automatic rifles. They instruct the group to put their hands up and demands to know who they are.
Thaddius shows the leader, Corporal Lang, his psychic paper and the Corporal salutes him as an Officer, though he is still curious how he got down here.
Karl is still rather dazed but begins to make comments about military cover ups and appears to distrust the soldiers.
Thaddius asks what they are doing and Lang tells them he has orders to place explosives here to blow up the station to block the advance of the “fungus stuff”, gesturing towards the tunnel where the web-goo is.
Corporal Lang arranges for one of the privates to escort Lieutenant Thaddius and his party back to HQ, while he remains behind with the other private to finalise the setup of the TNT.
The private escorts the travellers and Karl through the Underground, past Bank, where they switch from the Northern line to the Central line, as St Pauls, Chancery Lane and Holborn, where there is a forward base with a couple of soldiers on watch, supervised by Sergeant Osgood. Osgood stops the party and demands to know what is going on. The private explains this is a new Officer and he is escorting him to HQ at Goodge Street. Osgood is suspicious and examines the psychic paper of Thaddius. He seems to dismiss it, then he nods and allows them to proceed.
They continue to Tottenham Court Road, then return to the Northern Line to get to Goodge Street station. There behind the station, the Army has set up a HQ in an old wartime bunker.
They are taken to Captain Knight, the acting CO, who examines Thaddius’s psychic paper closely, but still accepts him as an Officer, though Knight out-ranks him. Knight is still confused by the way they are dressed and especially Karl, who continues to babble about zombies, aliens and military / government conspiracies, confusing everyone.
At one point, Thaddius mentions that he has seen this before in Tibet and at that point Knight begins to believe them. He says they will need to speak to the Professor, which Frederick expresses an interest in.
Frederick is taken to the laboratory, while Thaddius and Karl are taken by Knight to the Operations Room.
On the way to the laboratory, Frederick is intercepted by a journalist, Harold Chorley, who takes a big interest in him and wants to know all about him, asking many personal questions that Frederick is reluctant to answer. Chorley presses him for answers, but eventually Frederick gets away from him and proceeds to the laboratory.
When Frederick reaches the laboratory, he finds an attractive young technician / scientist working on various electrical devices there. Her name is Anne. He asks about who Frederick is and what he is doing here.
Then a grumbling old man enters from a side room, complaining to Anne he has lost something. Anne calls him Father and says she will help him find his missing equipment in a moment, she is speaking to their visitor.
The old man scoffs at the visitor, but Frederick suddenly recognises the old man as Travers – the European they met in Tibet. Professor Travers is taken aback when he recognises Frederick – it has been 30 years and Frederick looks no older!
They quickly start talking about old times and Travers brings him up to date on what has happened in London since. He brought back all the Yeti equipment to London, but none of it worked. He has spent the last 30 years trying to work out how it worked and trying to get it to work again.
Not too long ago he succeeded in getting one of the spheres to work. It quickly vanished and about a month later fog hit London and web started forming in the Underground. When a Yeti was sighted, Travers realised he needed to get involved and told the authorities all about his experiences in Tibet. They assigned him to the military task force trying to contain the problem in the Underground – Central London having since been evacuated.
They are not making much progress at the moment. The web fungus is closing in, taking over more and more of the Underground, and his efforts with the help of his daughter Anne have failed to locate the source of the Great Intelligence transmissions or find a way to block them.
Frederick offers to help as best he can.
Meanwhile, Captain Knight has been briefing Thaddius and Karl on the situation, telling them very similar history to that Frederick is learning. From a military point of view, their policy is to contain the fungus and the Yeti until the scientists are able to come up with a technological solution.
They have continuing difficulties getting supplies through and their latest supply drop, along with their new commanding Officer, is late and overdue at Holborn.
Their current plan is to blow up the tunnels down which the web fungus is slowly encroaching towards them, to delay its advance. There first attempt will be at Moorgate to block the advance down the Northern Line.
Thaddius and Karl resolve to go back to Moorgate to help Corporal Lang. They travel back towards that station, checking in with Sergeant Osgood at Holborn. He is ready to trigger the explosives when they give the word.
When they get to Moorgate, Corporal Lang tells them the explosives are primed and ready. Suddenly Yeti robots lumber out of the tunnels behind them – they have been followed to Moorgate by the Yeti.