Complex sentence: Reunited with an old partner (Keaton), Calvero gives a triumphant comeback performance but immediately suffers a heart attack and dies in the wings while just a few feet away from him Terry, the second act on the bill, dances on stage.
Split into simpler sentences: Reunited with an old partner (Keaton), Calvero gives a triumphant comeback performance. He suffers a heart attack during a routine, however, and dies in the wings while watching Terry, the second act on the bill, dance on stage.