Bill Dubuque ("The Judge") wrote the script about a mild-mannered accountant with Asperger's (Ben Affleck) who moonlights as an assassin.
Tambor will play a veteran Mafia accountant who acts as Affleck’s mentor – potentially in more than just money management.
Meamtime Deadline adds that John Lithgow will play Lamar Black, a tech magnate in the robotics field who hires Affleck’s character to look at his company’s accounting after some financial irregularities.
Anna Kendrick, J.K. Simmons Cynthia Addai-Robinson and former "The Walking Dead" co-star Jon Bernthal also star.
Gavin O'Connor is going to direct here.
Kevin Scott Frakes, Lynette Howell, Raj Brinder Singh and Mark Williams are producing the project.
Stuck for several years in development, the project was at one time considered for a directorial vehicle for Mel Gibson. At another point along the way Will Smith was attached to star.
Ben will take on the role that in begins soon before he directs and stars in the film adaptation of author Dennis Lehane's novel "Live by Night" which begins filming in July.