Politically motivated journalists, a mediaeval castle, the second World War, Margaret Thatcher's election, and a particularly nasty mythological creature are all connected in the 2011 Doctor Who audio play Rat Trap. Carried especially well by a performance from Peter Davison as the Fifth Doctor, this story is funny and sinister and ties its various threads together as nicely as a wad of rats' tails.
Maybe you've heard of the Rat King, the extremely rare case of a group of rats who've gotten their tails tangled up. In Rat Trap, a government scientist begins working in the aftermath of World War II to create a super-intelligent, telepathic being by experimenting with rats, connecting them in such a manner in the tunnels beneath Cadogan Castle. Intending to visit the middle ages and witness some jousting, the Doctor and his companions, Nyssa (Sarah Sutton), Tegan (Janet Fielding), and Turlough (Mark Strickson), find themselves beneath the castle in 1983 where a group of journalists are trying to uncover the truth about the place before it's taken over by Heritage in the wake of Thatcher's election and any unsavoury history can be hidden away.
Just this layering of concept is fun but the characters are nicely rendered, too. The group of journalists the Doctor encounters squabble and have distinct personalities--one had brought along a dog whistle to ward off any dogs when breaking into the castle, at which the Doctor wryly asks if they realise dog whistles attract dogs, not scare them away. Davison is in top form here and I was particularly impressed by his ability to speak great lengths of dialogue in a single breath. He usually played the Doctor as seeming almost out of breath and the impression he gave was of someone who's acutely conscious of time rapidly running out but whose sense of decorum insists that he say everything that needs saying in just the proper way. We see this in Rat Trap when, in rushing from one point to another, he manages to ask very quickly but very politely that he be reminded of a stash of napalm he'd left behind and that he should dispose of it properly when time allows.
Nyssa continues the plot thread started in Cobwebs that finds her much older than she was on the television show. She's given a moment to dramatically chew on the underused point about the Master possessing her father's body. Turlough, meanwhile, has an entertaining adventure in the TARDIS with a defibrillator.