Spenser Confidential is a 2020 American mystery comedy-thriller film directed by Peter Berg and with a screenplay by Sean O’Keefe and Brian Helgeland. It is very loosely based on the novel Wonderland by Ace Atkins, and uses the names of characters created by Robert B. Parker. The film stars Mark Wahlberg, Winston Duke, Post Malone, Alan Arkin, Iliza Shlesinger, Bokeem Woodbine, Cassie Ventura, and Donald Cerrone, and marks the fifth collaboration between Wahlberg and Berg after Lone Survivor, Deepwater Horizon, Patriots Day, and Mile 22.