"Without Warning” — a 10-track collaboration from 21 Savage, Offset and Metro Boomin — dropped Oct. 31 at midnight. The timely mixtape, peppered with Halloween-themed pop culture references from “Nightmare on Elm Street” to the Grim Reaper, gives hip-hop fans yet another reason to celebrate. Following recent high-profile releases like Young Thug and Future’s “Super Slimey," this fall season continues to heat up thanks to “Without Warning.” The mixtape’s deep wealth of talent and appropriately sinister themes result in non-stop bangers throughout. Metro Boomin, who produced each track on “Without Warning” and just released a new track with Big Sean, has been on a roll lately. The clean production of “Without Warning” reflects Metro’s talent for delivering cohesive but fresh tracks. At face value, a horror-themed rap album featuring the seemingly odd pairing of 21 Savage and Migos’ Offset could either be really horrible or surprisingly great. Thankfully, Metro’s magic touch transforms the potentially corny album into a respectably spooky experience. With heavy-handed 808s, eerie instrumentals and horror movie sound effects, the young producer expertly creates the perfect backdrop for 21 Savage, Offset and featured guests to do their thing. Metro’s past work with 21 Savage and Offset was straight fire, and he successfully reignites those flames on “Without Warning.” The producer’s lengthy discography includes legends like Kanye and newer artists like Lil Uzi Vert, speaking to his timeless and natural skill for showcasing unique talent instead of overshadowing it. While 21 Savage’s intense, mean approach to rap contrasts with Offset’s energetic demeanor, Metro manages to accentuate each Atlanta collaborator’s strengths and trademark style. With six shared tracks and two solo tracks each, 21 Savage and Offset complement each other, saturating the tape with balanced servings of hostility and playfulness. On shared tracks like “Still Serving,” written about 21’s incarcerated uncle, Metro’s ominous beats simultaneously highlight 21 Savage’s dark tones and Offset’s lively energy. The consistency of the evil Halloween theme ties the whole album together. 21 Savage’s infamously violent persona lends itself to this category of fare, while Offset’s spirited character adds flavor and life. With supernatural references and overwhelmingly haunting language, 21 Savage, Offset and Metro maintain relevance and unity. Some songs like “Nightmare” and “Darth Vader” are heavily influenced by the dark spirit of Halloween, but others are more loosely influenced. However, Metro’s production choices across “Without Warning” ensure that an eerie ambience haunts each track. No collaborators effectively outshine the others throughout the mixtape. The duets and solos alike consistently deliver frightening yet energetic vibes. Several tracks would succeed as standalones, but Offset’s “Ric Flair Drip” prevails as the most memorable and single-worthy song off “Without Warning.” The track’s spellbindingly quick beat blends with Offset’s unique pacing, resulting in an accessible yet fresh delivery. Offset uses this track to show off his skillful flow, with colorful verses drawing parallels between his lifestyle and that of former WWE star Ric Flair. Features from Quavo and Travis Scott elevate the joint efforts of 21 Savage, Offset and Metro Boomin to craft a truly forceful mixtape. Each artist contributes his distinct flow and sound, making “Without Warning” a forcefully cohesive album with clout to spare. “Rap Saved Me” featuring Quavo, a hypnotic track overflowing with braggadocio, allows the rappers to address their similar journeys to fame. But opening track “Ghostface Killers” featuring Travis Scott is the definite standout, with its aggressive beat, rich imagery and Scott’s memorable verse tying it all together. Thanks to its gripping hostility and abundance of talent from production to performance, “Without Warning” surprisingly delivers a gratifying selection of tracks for the Halloween season.