Original sentence: The Ainley Master also showed a knack for returning from death or eternal imprisonment, although how precisely he survived those seemingly final fates was never explained
Edited sentence: At the end of a number of adventures, the Master is seen to either die or be trapped in situations from which he was unable to extricate himself.How the Master has survived each of his seemingly-fatal encounters with the Doctor in this incarnation has never been explained.The use of the Master during the 1980s became highly problematic as the character appeared more and more frequently.These include the end of "The Trial of a Time Lord" where both he and his TARDIS are trapped inside the Matrix seemingly forever and his apparent "death" at the end of "Planet of Fire" where he is destroyed by the numismaton flame (originally written as Ainley's contract with the show had come to end and he did not intend to renew it)