Extra-creepy episode of Torchwood tonight as an alien infiltrates the team and modifies their memories so that they believe he’s always been with Torchwood.

Adam convinces Tosh that she’s in love with him, and changes Gwen’s memory so that she doesn’t remember Rhys. Jack starts to have troubling visions.

Gwen arrives home and Rhys comes out of the bathroom and creeps up behind her. He startles her, and she pulls a gun on him and asks why he’s in the flat. She calls Jack, who verifies that Rhys is telling her the truth. Back at Torchwood, Owen confirms that Gwen has lost her memories of Rhys.

Jack relates a childhood story to Adam of how he lost his brother Grey in an alien invasion in the 51st Century. He had buried the memories because they were too painful, although he spent years searching for his brother to no avail.

Owen becomes a nerd with a complete fixation on Tosh. At one point, when Adam is out of the way, he declares his love for Tosh, claiming that he “aches for her”. Tosh seethes that his outburst was inappropriate and storms out of the room.

Rhys and Gwen make a breakthrough when he loses his temper in a shop and she remembers his nickname - Rhys The Rant.

Elsewhere, Ianto discovers that Adam doesn’t exist in his diary, and realises that something is amiss. Adam attacks him and implants false memories that convince Ianto that he’s a serial killer. Yikes.

Jack is perched on top of a building reliving painful memories of his brother’s disappearance. He’s crouched over his father’s dead body when his mother arrives and asks where Grey is. Young Jack is pained and ridden with guilt.

When he gets back to Torchwood, Ianto begs Jack to put him into the vault, claiming to be a serial killer. Jack immediately realises something is wrong. Jack gives him a lie detector test, but everything Ianto admits to is detected as the truth. Jack refuses to believe it, saying that “something’s changed you. You’re not a murderer - I’m certain of it.”

Jack checks back on the CCTV footage and discovers Adam is the common denominator in everyone’s memory loss. When the team return, Jack shocks them all by putting a gun to Adams head and locking him in the vault. Adam initially begs for forgiveness, but ends up taunting Jack for “never forgetting the lives we’ve taken”.

In order to restore normality, Jack reminds everyone that their memories are false and asks them to remember a point in the past. He gives them short-term memory loss pills to erase the memory of Adam. They sleep and he goes to visit Adam, who tempts him with an offer to restore his happy memories of his father.

However, Adam tricks Jack and embeds himself in Jack’s last happy memory of his family together. Well, you think, but Jack still has one last memory loss pill left for himself. He takes it, and because no-one now remembers the alien, he cannot survive and disolves.

The team return to normal, despite noticing a two-day gap in their collective memories. Jack discovers Adams mysterious golden box and opens it up to reveal…sand. I’d imagine in Torchwood’s line of business, even sand should be viewed with suspicion, but Captain Jack just lets it flow through his fingers onto the desk. Where it will no doubt form so unspeakable alien creature that they’ll have to capture next week!

Anyway, the next episode brings Doctor Who sidekick Martha Jones into the plot. Looking forward to that one?