A 26th century geological expedition is ambushed underground, leaving only a single survivor. When she crawls her way back to the surface camp, she reports the massacre. A squadron of security troops arrives to investigate, but they also consider her a suspect. However, when the troops return to the subterranean caves to look for the evidence, they first find a pair of killer androids…and then they find four people claiming to be time travelers, who instantly become the prime suspects. But these travelers – the Doctor and his unharmonious trio of companions – are more of a threat to the plans of the Cybermen (once again wearing new suits of high-tech armor). It seems that, fearing an upcoming conference of interplanetary superpowers that could spell the end to the Cybermen’s war effort, the silver ones plan to slam a huge space freighter into the Earth, obliterating a large portion of the planet’s surface. But when Adric manages to thwart the Cybermen’s plans by accidentlly sending the freighter back in time (but still on the same trajectory), he’s either helping to prevent the human race from coming into existence…or ensuring that event.
written by Eric Saward
directed by Peter Grimwade
music by Malcolm ClarkeGuest Cast: Beryl Reid (Briggs), James Warwick (Scott), Clare Clifford (Kyle), June Bland (Berger), David Banks (CyberLeader), Mark Hardy (Cyber Lieutenant), Steve Morley (Walters), Suzi Arden (Snyder), Ann Holloway (Mitchell), Anne Clements (Trooper Bane), Mark Straker (Trooper Carter), Alec Sabin (Ringway), Mark Fletcher (Crewmember Vance), Christopher Whittingham (Crewmember Carson), Carolyn Mary Simmonds, Barney Lawrence (Androids), Jeff Wayne, Steve Ismay, Peter Gates-Fleming, David Bache, Graham Cole, Norman Bradley, Michael Gordon Brown (Cybermen)
Broadcast from March 8 through 16, 1982
LogBook entry & review by Earl Green
Review: Along with The Caves of Androzani, Earthshock is one of the two definitive highlights of the fifth Doctor’s era, offering a fantastic combination of relentless (and, given the BBC’s standards and the show’s budget at the time, very well-executed) action, surprise plot twists, and almost unbearable tension. The supporting cast is also top-notch, with comedienne Beryl Reid standing out in a very serious performance as the captain of the hijacked space freighter. Earthshock also marks the first appearance of David Banks as the Cyberleader, a role he would continue to play through the last Cybermen episode of the classic series, 1988’s Silver Nemesis.
To the surprise of many viewers at the time the show first aired, this was also the last live-in-the-flesh appearance of Matthew Waterhouse as Adric. (He later appeared as ghosts or visions of Adric in the following story, Time-Flight, and in Caves of Androzani.) Despite the signature 1980s whining-companion syndrome 
that pervades the early TARDIS scenes, Earthshock is easily the best performance, not to mention the best narrative use, of Adric since his introduction in Full Circle just the previous season. In Earthshock, Adric is intelligent, petulant, compassionate, and ultimately sacrifices his life to save the planet for which the Doctor has demonstrated his concern and affection. His final scene in episode four, at least in my eyes, is worthy of a tear in the eye…but then again, I am very much in the minority in that I genuinely liked Adric as a character. Most of Doctor Who fandom doesn’t care for the lad, but the writers didn’t always have a clue how to use him, so I can see where that segment of fans is coming from. But the Adric of Full Circle, The Keeper of Traken, Logopolis and Earthshock is a character I missed.
Malcolm Clarke‘s pulsating electronic music for Earthshock is his first contribution to Doctor Who in the 1980s, and though some of his cues for Cyberman-related scenes recall the abstract music from 1972’s The Sea Devils, he creates a downright hummable theme for the Cybermen – the best musical signature they’ve had since the 1960s episodes which tracked their appearances with the stock “Space Adventures” tune.