Complex sentence: On April 30, both Morena Baccarin and Allison Janney joined the cast of the film, Baccarin will play one of the agency's top deadly spies, while Janney will play top CIA agent Elaine Crocker.
Split into simpler sentences: On April 30, both Morena Baccarin and Allison Janney joined the cast. Baccarin played one of the agency's top deadly spies, while Janney played top CIA agent Elaine Crocker.