Tom has fallen in love with someone he'd only just met during a random adventure, so Panda and Iris are travelling alone. Iris gets all nostalgic for early 20th century music and feels a strange urge to go visit the DJ of an intergalactic oldies station, Sam Gold. Panda's reluctantly dragged along as Iris parks her TARDIS inside the station and walzes in, to go give some interviews about her extensive and intimate knowledge of earth musicians.
While Panda gets his drink on with station page girl Lisa, Iris meets Sam... who turns out to be her husband. One day into their honeymoon on Dark Space Eight, Iris popped off to check on her TARDIS for a bit, got caught up in an intergalactic baking incident, and never returned. Since her recent memory issues still plague her, she has absolutely no idea what happened next. But whereas Sam's misery (and subsequent downfall in his career) lasted six months, Iris is pretty sure it's been a few decades for her. She simply doesn't know how to connect with Sam again. For old times' sake, they give it a go with a nice bottle of champagne.
Lisa, meanwhile, turns out to be the unwilling minion of an evil alien entity (a Naxian), which plans to steal Iris' TARDIS. The entity's plan is to infuse the station's music with mind-control bits and influence the entire galaxy. It's been doing so for months now though the knock-off music composed by the station synthellect, Janice (since the station can't afford actual 20th century music). Now that it's got a time traveller nearby, though, it's got a much better plan: vworp aspiring singer Lisa back to 1960, and use Sam's encyclopedic knowledge of rock music to write every known hit song for her years before it's supposed to come out. With a few adjustments to her vocal cords, Lisa's voice can control earth's entire population.
Iris is forced to take Lisa on board her bus while Panda and Janice stop the alien invasion at the station. As soon as Lisa actually sees the 1960's, though, she's so awed by its beauty that she can throw off the mind control. Unfortunately, Sam makes a Heroic Sacrifice to protect Iris from the impact. Iris is very shaken by the experience, but decides to throw him the greatest funeral ever.
Tropes:
- Easy Amnesia: Iris is still having some memory problems after the previous season. It comes back to bite her.
- I Coulda Been a Contender!: Lisa.
- Lampshaded Double Entendre: Iris makes a rather stealthy pun about sitting on top of a legion of Roman soldiers.
- Internal Homage: The entire episode is one to "Bang-Bang-a-Boom!".
- Put on a Bus: Tom, in a parody of how many Doctor Who companions (Vicki, Leela, Mel...) ended up leaving the TARDIS.
- In particular, the circumstances in which he fell in love deliberately parody the way Iris actress Katy Manning's character Jo Grant left the TARDIS.
- Riches to Rags: Famous DJ Sam lost the will to do much of anything at all after Iris disappeared, and ended up a neglected DJ on a crap station.
- Totally Radical: Janice.
