Muriel (the journalist) realised that on the spine of the Liber Ivonis, there was a message encoded in some kind of code using small bumps that she had learnt at the Guides. It said "USE THE PLUCKLEY PAPERS M". Obviously, to her, this referred to some pages of ancient manuscript that she read as a child in her uncle's, Lord Pluckley's, library. So, on the way to Margate, to see Fred Russell, they drop in to renew acquaintances. They meet Muriel's old playmate and cousin Chastity who is now a Nazi sympathiser. Also, it appears that her younger brother Vernon, who is in with Lord Rothermere (of "Hurrah for the Blackshirts", Daily Mail, fame) and several Germans including Princess Stephanie von Hohenlohe and von Neurath, junior attaché at the German embassy and son of the German Foreign Minister. Muriel finds that Vernon has swiped three of the pages but that Morton the butler interrupted him and prevented him from taking the fourth. Muriel swipes this. It seems that Vernon has passed the document onto his Nazi chums for the Thule-Gesellschaft to investigate. They also chat with Pluckley who seems a nice old duffer, not like his children at all.
The page talks about the Sign of Kish, some kind of protective amulet in the shape of a star. The archaeologist remembers seeing one on the café wall in Embankment Gardens. The doc is despatched to retrieve it which he does for £4.
Next, in Margate, the find Fred in the pub and, posing as the doc's oppos, get his story. He had a vision of the twisted bodies being dumped in the grave in Tudor times. One, swaddled in bandages and tied with rope was still struggling. It had this star amulet affixed to it, to stop it escaping some how. When Muriel mentioned that she had seen this thing in the river, he freaked out and needed to be reassured.
Back in London, they meet up with the rest of the crew. The archaeologist has called in a MoD chum who moves in the same lofty circles as the Pluckleys. In the discussion, Muriel realises that the message from the past is something she must have written to herself, the code used is barely 150 years old but the binding had been in the earth for 400!
They decide to split up. The crook and the MoD bloke go to Vernon's club, the Carlton, opposite the German embassy, the other men to the Dorchester. Muriel goes home to rest and is tailed by one of the false journalists. She clocks him and holds him up with her gun. He's very tame and scared. He belongs to the IPC, an occult group, the International Psychics Club, who are investigating events related to the occurences in March 1925. He doesn't appear to know very much but is bullied into acting as Muriel's mole within the club.
Nothing much doing at the Carlton Club but at the Dorchester, the archaeologist and doc persuade Vernon, the Princess and friends that they are sympathisers, interested in getting more occult material for the Thule-Gesellschaft. They find out that the papers are in the embassy, soon to leave for Germany. When they leave, the archaeologist is followed, they are checking his credentials.
That night they raid the embassy, drugging the ambassador's pet alsatian, cracking the safe in von Neurath's office, replacing the papers with fakes, unfortunately they are spotted by the watchdog, at rat thing which attacks the doctor. There is some scuffling but the archaeologist even sees it telephoning for help. They try to cover their tracks with a bomb but the whole building is alerted and Giro is unfortunately electrocuted during their escape.