After four albums for Prosthetic Records, the Houston prog-metal group Scale the Summit get mathy and intricate on the self-released In a World of Fear. This set conjures distinct sound worlds with crystalline production (“Astral Kids”), labyrinthine guitar lines (“Cosmic Crown”), and tortuously heady rhythms (“Witch House”). Tracks like “Opal Bones” blend airy ambiance and exemplary heavy-metal riffs to create otherworldly textures, while the closer “The Warden,” with its ornate guitar melodies, harks back to classic ’80s progressive metal.