Torchwood/Recap/S2/E13 Exit Wounds
Jack's ex-boyfriend, Captain John Hart, is back at the Hub. He kills Jack, ties him up using Time Agent handcuffs and generally acts like a jilted ex-lover.
John blows up the city. Gwen, Rhys and Sergeant Andy mobilise the Welsh police force.
Eventually, John takes Jack all the way back to 26 A.D., where Gray is waiting for them. It turns out that John has a bomb grafted into his skin, planted there by Gray. His over-the-top "Psycho Ex Boyfriend" act was supposed to be a hint to Jack, because Gray was listening in all along.
Gray and Jack have a tearful reunion, but Gray needs closure and revenge. He starts off by killing Jack, then tells him that he's spent his whole life so far being tortured, after Jack lost track of him in that air raid. He wants Jack to be buried underneath Cardiff forever. Jack reluctantly agrees, seeing no way out, and John is forced to do the burying. However, John throws in a ring as well, claming it's a sentimental thing.
John is freed of the bomb, warps to present day and immediately calls Tosh and tells her to do a scan for the ring's signal. Nothing shows up. Gray appears in the Hub and shoots Tosh. Meanwhile, Owen is trying to cool down the city's fragile nuclear power plant.
There's tapping and banging from Torchwood's morgue... and it's Jack. His burial site was found by Torchwood technology in the early 20th century, and he decided to let himself be frozen and locked up in the Hub (with a timer) so he wouldn't have to spend the next few decades avoiding himself.
Tosh remotely guides Owen through the power plant system, but he's locked in, and his body will be destroyed. He and Tosh say their final goodbyes, reminiscing about that time with the space pig and that date they never really had. Tosh doesn't tell Owen that she's dying as well.
Jack neutralizes Gray, forgives him, and locks Gray's comatose body in the morgue. John kisses Jack on the cheek and steps out of his life again. Tosh's pre-recorded "if you see this, I'm dead" message plays, and everybody cries.
From here, the story segues into Doctor Who.