Complex sentence: Pentangeli meets the Rosatos; their men ambush him, saying they act on Michael's orders, but a passing policeman interrupts them and they flee, leaving Pentangeli for dead.
Split into simpler sentences: Pentangeli meets the Rosatos, and their men ambush him, saying they act on Michael's orders. However, a passing policeman interrupts them, and they flee, leaving Pentangeli for dead.