Tissue Compression Eliminator

The Tissue Compression Eliminator (or TCE) was a trademark weapon of the Master, especially after he assumed the appearance of the Trakenite Tremas. (TV: The Keeper of Traken)

As its name suggested, the TCE killed by drastically compressing the bodies of its targets to the point where life functions ceased. The Master liked to leave the shrunken doll-like corpses of his victims as a calling-card for the Doctor to discover.

The Fourth Doctor once described the method by which killed as "matter condensation". (TV: The Deadly Assassin)

once materialised his TARDIS within UNIT HQ and attacked the Third Doctor. In the brawl, the Doctor took the TCE and the Master fled. The Third Doctor threatened the Eighth Doctor with the TCE, hoping he would hand over the TARDIS. Ultimately, he decided against it and handed the device to his future self. (PROSE: The Eight Doctors)

later attempted to improve the design of his weapon, but a laboratory accident resulted in the laboratory and him both being reduced in size instead. This did not appear to harm him. (TV: Planet of Fire)

Izzy Sinclair was shrunk after being shot with a TCE without being killed outright by 's disciple Sato Katsura. She was later able to use the weapon to reverse the process. (COMIC: The Glorious Dead)

On another occasion the Master used the TCE against a velociraptor revived by the fountain of youth. However, it landed right back in the fountain, re-emerging unharmed but miniscule in size, making a comical sight. (PROSE: A Town Called Eternity)

The TCE, despite its name, was equally capable of shrinking inorganic tissue: victims' clothes were also shrunk. On one occasion, demonstrated the weapon by shrinking empty space-suits. (TV: Planet of Fire)

Eventually, the victims of TCE were no longer visible after the exposure. The Sixth Doctor stole and used it to threaten and the Rani; later Peri Brown did the same. (TV: The Mark of the Rani)

The Fifth Doctor was able to use the TCE to sabotage 's TARDIS. (TV: The King's Demons)

During his first encounter with the artificially-enlarged mechanoid freelance peacekeeping agent Death's Head, the Doctor used a TCE (which he happened to have on him) to defend himself against the mercenary. Death's Head was not injured, but found himself returned to his original size (that of a normal humanoid), which he remained for the rest of his career. (COMIC: The Crossroads of Time)

The TCE was used by Es'Cartrss of the Tactire through a simulated reality in the Matrix of the Doctor's TARDIS, while posing as the Valeyard (COMIC: The Forgotten)