Blind spots are dangerous. They can obscure critical flaws. But what makes them insidious is you often don’t recognize them.

I say this as a way of apologizing for Daniel Isn’t Real, a well-executed thriller with a fatal flaw I suspect director and co-writer Adam Egypt Mortimer never saw.

The story concerns Luke, a mopey collegiate played by Miles Robbins. As his life becomes more stressful, he reconnects with his childhood imaginary friend Daniel, played by Patrick Schwarzenegger. At first, the charismatic Daniel provides the companionship and guidance Luke craves, but Luke soon suspects Daniel may be more than imaginary and with less than genteel motives.

It’s a twist on the Fight Club story. Schwarzenegger plays Daniel as a mix of comedian Anthony Jeselnik’s stage persona and Christian Bale’s turn in American Psycho. The charismatic predatory confidence proves entertaining. Mortimer never cheats, setting the rules for how Daniel works then abiding by them. To this end, he overcomes what I suspect was his biggest perceived hurdle: how to integrate the imaginary and the real. It’s a trick Fight Club glossed over with some hand-wavy flashbacks.

But in focusing on this aspect, Mortimer missed the film’s biggest problem: as compelling as Daniel is as a character, Luke proves just as uncompelling. In Fight Club, Edward Norton’s character opens the film sleepwalking through life, but as his relationship with Tyler grows, he takes more agency. Consider the comedic scene where he confronts his boss and frees himself from the 9-to-5 grind. Seeing him take action endears him to us.

Luke has no such arc. He lacks agency throughout. The film introduces disposable characters to ask the questions or take the actions Luke should. He’s a whiny, mopey sad sack. We feel sorry for him but never root for him.

This comes to a head in the film’s ludicrous third act. Having your leads sword fighting atop a New York brownstone should have been warning enough, but that’s the thing about blind spots. You don’t know what you don’t know.