Complex sentence: Along the way, Mack & Moxy meet a new Friend-In-Need who introduces Mack & Moxy (and the kids at home) to a new important cause.
Split into simpler sentences: Along the way, Mack & Moxy meet a new Friend-In-Need. The Friend-in-Need introduces Mack and Moxy (and the audience at home) to a new and important cause.