After a few notable misfires, M. Night Shyamalan made a bit of a comeback with low-budget thriller Split, which revealed itself to be set in the same universe as the director's own 2000 film Unbreakable right at the end, thereby promising an upcoming crossover.

Glass is M. Night Shyamalan's attempt to combine both films, paying homage to comic-books and their shared universes along the way while delivering the Unbreakable sequel he'd always planned to make. The core idea of this film is an interesting one: a superhero and two supervillains are trapped in a mental institution where a doctor, Dr. Ellie Staple (Sarah Paulson), attempts to convince them that they are, in fact, not all that extraordinary and possibly inflating what they're capable of in their minds. Elijah/Mr. Glass (Samuel L. Jackson) is kept docile with drugs for a good portion of the film while Kevin/The Horde's (James McAvoy) more dangerous personalities are kept in check using flashing lights.

This is a smaller scale movie than some might expect as 90% of it takes place in the hospital but Shyamalan keeps the mystery building at a decent pace and the cast delivers captivating performances throughout so don't expect it to feel too claustrophobic, especially when the surprises start happening.

The slow build-up of the film is, indeed, very good and, for the most part, the combination of Split and Unbreakable works very well. James McAvoy brings another no-holds-barred, wacky as hell performance to the table, Samuel L. Jackson is appropriately intimidating and Sarah Paulson is reliably good all-around, right at home in this American Horror Story-style scenario. Bruce Willis isn't given too much to work with but he also has his moments and there are some cleverly sly references to some of his films thrown in. Unfortunately, the film not only runs out of steam once the characters finally exit the institution but it actively goes out of its way to ruin itself.

The ending we are promised from the get-go, a showdown on top of a newly built Osaka Tower, never happens and we are expected to settle for a rather silly confrontation on the institution's front lawn before a couple of thoroughly mindless, and frankly dire, "twists" are revealed, undermining what was actually a worthy crescendo. One wonders whether the film ran out of money and the director went into damage control or if this was an attempt to provide a deceptively cerebral anti-climax that horribly backfired.

While fans of both Split and Unbreakable will find elements of Glass to enjoy from the good performances to the idea of a philosophical exploration of comic-books set in a hospital, the ending is so underwhelming and so inept that you'll likely leave the theatre wondering why you ever liked any of this in the first place.

Extremely disappointing.