Jack and Tosh investigate an old dance hall where one can apparently hear mysterious 1940s music. They find themselves transported into, of all times, just before the Blitz, at a lovely going-away party for soldiers.
The rest of the crew are starting to get a little worried. The rift over Cardiff is spiking in activity lately, and they can't get in touch with Tosh to let her know. Gwen can't find them at the dance hall.
Back in 1941, Jack gets into a small scrape with a soldier, but his handsome superior breaks up the fight, introducing himself to Jack and Tosh as... Captain Jack Harkness. At that point, a nearby creepy old man takes a picture of the Captain and our wayward travelers, a picture that Ianto and Owen notice when going through old files of the dance hall.
So, with the only real plan being to open the rift, but Tosh having half of her magical equation to open it on her laptop, she scrawls down what she can get out before the battery dies. But they're interrupted by the old guy who took their picture: the caretaker, Bilis. After they make their excuses as to their odd behavior and leave, the caretaker pulls a file out of his desk named "Torchwood". Also, Tosh is predictably a fish-out-of-water as the only "Jap" at a 1940's soldier party, but Jack introduces her as an English intelligence officer. He also admits to Tosh that he's been in this war before.
Cut back to Gwen outside the dance hall in the present, trying to figure out her next move, when the same Bilis pops up out of nowhere and asks if he can help.
While Tosh gets the equation ready to send into the future, Jack bonds with the real Captain Harkness. It turns out that Jack, when he was still a con man, saw Captain Harkness' name on a list of the dead, and stole his identity. Because of this, he knows that his new friend will die soon — tomorrow, in fact.
Time starts slipping as the bombs start dropping and Tosh is only able to get out part of the message. She hides the remainder, this time scrawled in her own blood, in a coffee can in the bunker. Gwen finds it, but our friend Bilis scratched out the last few numbers in the interim.
Jack has urged Captain Harkness to go spend what may be his last night alive with his girlfriend. Captain Harkness stays at the party instead and gently takes Jack's hand in makeout corner.
Owen, now losing it over the prospect of getting Diane back, is willing to open the rift and risk the whole universe collapsing. Despite Ianto threatening, punching, and shooting him, the Rift Manipulator is activated.
Jack and Captain Harkness share an intimate dance. A giant blue shining time portal opens in the dance hall. Jack walks towards it, takes a good look at Captain Harkness and kisses him passionately. Everyone looks at the men making out instead of at the massive space/time rift. Captain Harkness salutes Jack, and the gang is reunited in present day. With a gaping hole in the time stream.
- Continuity Nod: Several to parent show Doctor Who.
- There's a "Vote Saxon" poster on the door to the Ritz Dance Hall that Jack and Tosh first show up at. Given that this episode is set chronologically before that plotline came to fruition in the parent show (though only just), anyone watching both shows for a second time would notice the poster's significance almost immediately.
- Also, there is some graffiti that says "Bad Wolf"
- Jack mentions this isn't the first time he's been involved in World War II.
- Couldn't Find a Pen: Or rather, blood doesn't fade like pencil does. Ouch, Tosh.
- Dead Person Impersonation: Jack took the real Harkness' name after his death.
- E = MC Hammer: Tosh's equation to open the rift seems to be a few lines of calculus. Who knew it was so simple?
- Even the Guys Want Him: Our Jack is even able to make his namesake give him a big wet one.
- Get Back to the Future
- Love Theme: The music that plays over the dance between Jack and the real Captain Jack is "Jack's Love Theme." Fragments of it are used later in the series, notably over Jack/Ianto scenes and in transformed form in "The Ballad of Ianto Jones."
- Meanwhile, in the Future
- No Equal-Opportunity Time Travel: Averted, as Tosh does get some undue attention for being Japanese in the United Kingdom in 1941.
- Tosh even notes that her situation is going to get much worse if she's stuck in the past, as "Pearl Harbor is a few months away." (Technically the UK went to war with Japan after the attacks on Malaya, Singapore and Hong Kong; these happened the day after Pearl Harbor.)
- "Not So Different" Remark: Owen calls out Ianto on this. When Ianto claims Owen's opening the rift for Diane's sake, Owen fires back that Ianto's situation was hardly any less dangerous over someone he loved.
- Oh, Crap!: Jack has a look of total shock wash over him when his fake identity is revealed, as does a completely gobsmacked Tosh.
- Rustproof Blood: Tosh's note is still quite red seventy years later. Granted, this is Hand Waved by a comment about storing it in an airtight container, but it's questionable how much difference that would have made.
- The Big Damn Kiss: Jack and his namesake get a pretty epic one in, violins playing and everybody watching and everything.
- Wham Episode: Huge. "Jack Harkness" is NOT Jack's real name- he's been borrowing it all along. On top of that, Owen's still not over Diane's departure, really fucks things up the arse in the present day by tampering with the the Rift, and Ianto shoots Owen when he tries to stop him. But that's not the worst of it- the seemingly ordinary caretaker Bilis Manger is nothing of the sort. He's actually the Big Bad, preparing to summon a Greater-Scope Villain.
- Write Back to the Future