Complex sentence: Meanwhile, as the rest of the group calls for Toomey, Dinah discovers him hiding behind a counter advising him to come out, he escapes his bonds and stabs Dinah in the chest, leaving her critically wounded.
Split into simpler sentences: Meanwhile, as the rest of the group calls for Toomey, Dinah discovers him hiding behind a counter advising him to come out. He escapes his bonds and stabs Dinah in the chest, leaving her critically wounded.