Complex sentence: In the 1944 film "Henry Aldrich, Boy Scout", Holt played an unscrupulous Senior Patrol Leader, Irwin Barrett, who sabotages a competing troop in a wilderness orienteering competition, almost costing Henry and another Scout their lives.
Split into simpler sentences: In the 1944 film "Henry Aldrich, Boy Scout", Holt played an unscrupulous Senior Patrol Leader, Irwin Barrett. His character sabotages a competing troop in a wilderness orienteering competition, almost costing Henry and another Scout their lives.