Three children force a classmate to a test of courage to get into their group. During the test, which consists in finding a skull in an abandoned church, the child is swallowed by a chasm that opens on the church floor. The other kids, who had stayed out, rush in the church, look in the deep hole, call their friend, but don't receive answers. The little sister of one of them, who followed them, bursts into the church and lets herself down by a rope, but falls into the abyss, dragging the other kids. All five children find themselves into old caves in search of a way out, helped by Grotto, a creature alike a stalagmite.
Unfortunately the movie Grotto is not yet available on HBO Max.
| Production | Micol Pallucca | Producer |
| Sound | Alberto Buffolano | Original Music Composer |
| Directing | Micol Pallucca | Director |
| Sound | Francesco Cerasi | Original Music Composer |
| Writing | Micol Pallucca | Screenplay |
| Camera | Maxime Alexandre | Director of Photography |
| Costume & Make-Up | Andreea Dumitrescu | Hairstylist |
| Editing | Andrea Baracca | Colorist |
| Crew | Massimiliano Sperati | Driver |
| Sound | Francesco Cerasi | Music |
| Art | Monica Cappiello | Assistant Property Master |
| Crew | Taketo Gohara | Mixing Engineer |
| Production | Fabiana Compagnucci | Payroll Accountant |
| Crew | Claudio Trotti | Manager of Operations |
| Sound | Andrea Colaiacomo | Boom Operator |
| Production | Andrea Biscaro | Producer |
| Costume & Make-Up | Allegra Albanese | Assistant Costume Designer |
| Camera | Paolo Forti | Grip |
| Crew | Stefano Colaprete | Compositor |
| Production | Eleonora Muoio | Assistant Production Manager |
| Production | Marie Adler | Executive Producer |
| Camera | Rosario Balistreri | Digital Imaging Technician |
| Camera | Titi Gavrila | First Assistant Camera |
| Sound | Alberto Buffolano | Music |
| Production | Veronica D'Aloisi | Production Supervisor |
| Sound | Claudio Marani | Sound Editor |
| Crew | Mattia Gariglio | Video Assist Operator |
| Visual Effects | Daphne Mereu | Visual Effects Coordinator |
| Directing | Mirko Urania | First Assistant Director |
| Crew | Gianluca Petrazzi | Stunt Coordinator |
| Crew | David Zamperla | Stunt Coordinator |
| Directing | Livia Menichelli | Script Supervisor |
| Visual Effects | Alessandro Contenta | Animation Supervisor |
| Visual Effects | Giampaolo Fragale | Animation |
| Crew | Marco Tripodi | Compositor |
| Editing | Consuelo Catucci | Editor |
| Art | Maurizio Marino | Property Master |
| Camera | Angelo Donatone | Grip |
| Lighting | Michele Edoardo Scotto D'Abbusco | Electrician |
| Visual Effects | Claudia Casapieri | Animation |
| Costume & Make-Up | Valentina Mezzani | Costume Design |
| Camera | Massimo Galiano | Key Grip |
| Crew | Roberto Saba | Compositor |
| Directing | Federica Aresi | Second Assistant Director |
| Crew | Alexis Arts | Special Effects |
| Crew | Mirko Zamperla | Stunts |
| Crew | Fabio Vita | Driver |
| Sound | Vincenzo Urselli | Sound |
| Camera | Maurizio Benvenuto | Grip |
| Crew | Luca Della Grotta | CGI Supervisor |
| Visual Effects | Paolo Virgilio Demurtas | Animation |
| Writing | Micol Pallucca | Writer |
| Lighting | Leonardo Fanone | Gaffer |
| Editing | Maddalena Colombo | Assistant Editor |
| Sound | Mauro Eusepi | Foley Artist |
| Crew | Lena Di Gennaro | Compositor |
| Crew | Gianvincenzo Morabito | Post Production Supervisor |
| Production | Leonardo Carletti | Accountant |
| Editing | Giuseppe De Tullio | Assistant Editor |
| Sound | Claudio Marani | Supervising Sound Editor |
| Visual Effects | Rodolfo Migliari | Visual Effects Supervisor |
| Production | Fulvio Compagnucci | Producer |
| Art | Fabrizio D'Arpino | Art Direction |
| Costume & Make-Up | Andreea Dumitrescu | Makeup Artist |
| Sound | Gabriele Fasano | Sound Effects Editor |
| Lighting | Leonardo Brocato | Electrician |
| Production | Davide Conigli | Production Assistant |
| Editing | Massimo Gubinelli | Colorist |
| Camera | Emanuele Parrini | Second Assistant Camera |
