Possible Clues:

• Ludlum protagonist
• Role for Damon
• Three-time role for Damon
• Two-time role for Damon
• 'The -- Identity' (Matt Damon film)
• Ludlum spy Jason
• Damon appears as him in five films
• "The ___ Identity"
• "The ___ Identity" (Ludlum novel)
• Action hero Jason in three Ludlum novels