**"Other Mommy" is slated for wide theatrical release on October 9, 2026, positioning it as a major mid-October horror title from Blumhouse and Atomic Monster.** With no reviews posted yet on Rotten Tomatoes, trader sentiment centers on the film's strong pre-release profile: Rob Savage directing from a script by Succession writer Nathan Elston, adapting Josh Malerman’s 2024 novel Incidents Around the House, and Jessica Chastain in a dual role as mother and the sinister entity. Recent momentum includes the second official trailer dropping mid-September and a featurette highlighting Chastain’s involvement, alongside supporting cast like Jay Duplass and Dichen Lachman. Historical patterns for similar high-concept Blumhouse/Wan horror entries show scores often hinging on critic reception of practical effects, tension, and originality versus genre tropes once embargoed reviews appear in early October.