Complex sentence: In "Last of the Time Lords", Martha Jones claims that the Torchwood Institute and U.N.I.T. created a gun and four phials of coloured chemicals, when slotted into the gun and injected into a Time Lord, will kill the Time Lord and prevent regeneration.
Split into simpler sentences: In "Last of the Time Lords", Martha Jones claims that the Torchwood Institute and U.N.I.T. created a gun and four phials of coloured chemicals. When slotted into the gun and injected into a Time Lord, the mixture will kill the Time Lord and prevent regeneration.