The main task involves researching, planning, filming, editing, and evaluating to create the opening sequence for a new thriller movie in groups of up to 4 students. This task makes up 50% of the AS level and is worth 100 total marks, with 20 marks allotted to research and planning, 60 marks for construction, and 20 marks for evaluation. Students must complete research and planning before half-term, filming during half-term, and editing and evaluation after half-term.