Complex sentence: Eugene steps up his torment of Meg and turns up at her apartment later in the week and injures Meg and guns down and kills her best friend Tracy and this causes Meg to have an emotional breakdown when she regains consciousness.
Split into simpler sentences: Eugene steps up his torment of Meg and turns up at her apartment later in the week, injures Meg, and guns down and kills her best friend Tracy. This causes Meg to have an emotional breakdown when she regains consciousness.