War of the Cybermen

War of the Cybermen is the tenth episode of the sixth series of Doctor Who. This episode marks the on-screen return of the Mondasian Cybermen, last appearing in Silver Nemesis.

Synopsis
"Cybermen from parallel Earth are inferior. We are the true Cybermen!" - Cyber-Lord

Deep within the glaciers of Greenland, a probe containing a TARDIS-like vortex manipulator has been unearthed. Coincidentally, a ship has been found directly beneath it. Both hold nearly exactly the same thing. The probe houses a stasis chamber of hundreds of Cybermen from before Mondas' destruction. The ship contains hundreds of Cybermen from a parallel universe. Both have been awakened, and once the two variants clash - the winner will get Earth.