This is the second film to co-star Liam Neeson and Colin McFarlane. The first was Batman Begins (2005). Ironically, both films feature scenes with Neeson on a commuter train that derails.

Vera Farmiga and Patrick Wilson's third collaboration after The Conjuring (2013) and The Conjuring 2 (2016).

Liam Neeson and Sam Neill were both contenders for the role of James Bond in GoldenEye (1995), which eventually went to Irish actor Pierce Brosnan. Neill was also considered for Bond in The Living Daylights (1987). Additionally, both actors starred in a Steven Spielberg film in 1993 (Schindler's List (1993) and Jurassic Park (1993)).

The second film to feature Vera Farmiga and an incident on a commuter train. The other being Source Code (2011).

Fourth collaboration between Jaume Collet-Serra and Liam Neeson after Unknown (2011), Non-Stop (2014) and Run All Night (2015).

Reunites Liam Neeson and Patrick Wilson, who both starred together in The A-Team (2010).

Second collaboration between Jaume Collet-Serra and Vera Farmiga after Orphan (2009).

Liam Neeson and Elizabeth McGovern's first collaboration since Clash of the Titans (2010).

A major plot point is the search for a character named "Prynne," which as Liam Neeson's character discovers, is derived from the Hester Prynne character in The Scarlet Letter, which the character is reading. A major police character in the film is named "Hawthorne," this is likely a reference to the man who wrote The Scarlet Letter; Nathaniel Hawthorne.