Complex sentence: Unfortunately, Michelangelo overhears their conversation and tells Raphael; furious, Raph takes Mikey, April, Casey, and Vern and breaks into police headquarters to recover the mutagen.
Split into simpler sentences: Unfortunately, Michelangelo overhears their conversation and tells Raphael. Furious, Raph takes Mikey, April, Casey, and Vern and breaks into police headquarters to recover the mutagen.