Matthew MacFadyen is returning to Spooks for the very final episode.
The Three Musketeers star played MI5 agent Tom Quinn in the very first series of the BBC show, but left at the beginning of series three, when Tom was decommissioned and started his own private security firm.
Matthew will return as Tom in the last episode of the tenth and final series, which airs on Sunday October 23 on BBC One.
Matthew met his wife Keeley Hawes on the set of Spooks as she played fellow agent Zoe Reynolds.
It is not known why Tom is back in the show, as viewers await an ending to the latest exciting cliffhanger which saw Spooks head Harry captured by the CIA and extradited to the US.