Many incarnations of the Doctors and their old companions are taken out of time and deposited in the Death Zone on Gallifrey. There, they must battle the Master, Daleks, Cybermen and Yeti in order to reach the Dark Tower and discover the Tomb of Rassilon.
Is it a celebration of Doctor Who? Yes! Does it have some really pleasant moments of nostalgia? Yes! Does it do anything beyond that? Nope! The Five Doctors is pure nostalgia fest, with a bit of Time Lord lore thrown in on top. The plot is incredibly lightweight, with only the Fifth and First Doctors actually driving the events. The Second and Third Doctors pretty much spend their time trying to get to a Tower, while lots of nostalgia happens, including Yeti, Cybermen, The Master, The Brigadier, Jamie, Zoe, Sarah-Jane, Liz Shaw, Mike Yates and Bessie. The problem with these kind of stories is they spend so much time showing off old things, that there’s no time to progress the plot. It’s completely fine if you just want to reminisce about some of the finer aspects of Doctor Who, including Patrick Troughton and Jon Pertwee’s performances. To be honest, you need these elements to distract you, because the more you think about the plot, the less sense it makes. The direction is pretty