Complex sentence: The snooping April witnesses their transformation, and is able to steal the vial of mutagen; pursued by the Foot, she is unexpectedly saved by Casey Jones, but in the scuffle, the vial is lost and taken into police custody.
Split into simpler sentences: The snooping April witnesses their transformation, and is able to steal the vial of mutagen. In the scuffle, the vial is lost and taken into police custody.