Despite the regeneration television audiences would see the First Doctor on screen for several more occasions (not counting flashbacks or charity specials like "Dimensions in Time"). For the 10th anniversary of the programme in 1973, Hartnell appeared in "The Three Doctors", which also saw Patrick Troughton reprise his role as the Second Doctor. Due to failing health, however, Hartnell could not participate in any of the regular filming, so his scenes were shot separately at Ealing Studios (not his garden or garage at home, as long suggested by fan legend); in the context of the episode, this is explained as the First Doctor being trapped in a time eddy when he was being sent to assist his future selves, with the result that he can only communicate with his future selves for brief moments over the TARDIS monitor while sitting in a capsule.