In New Who the Doctor travels to almost the very end of time and encounters the kindly Professor Yana.
You are not alone, the Doctor was once warned and sure enough memories start to bubble to the surface. The situation becomes clear when the familiar fob watch appears.
The first edition of The Masters fob watch came with a Derek Jacobi signature certificate. If you want one then you’ll have to find a specialist dealer and try and bargain for one. Good luck.
The signature free version of the watch is due to ship shortly and may also sell out. You can pre-order at places like Forbidden Planet.