Just when I have Guillermo del Toro pegged – not in a bad way, his films are often amazing – the man reinvents himself. Transforming the monster movie genre into a love story, “The Shape of Water,” produced, co-written and directed by del Toro, is the most charming film of the year, an adult fairy tale filled with just as much joy and beauty as grim moments.

Imagine if a seedy government agency captured the creature from the Black Lagoon and performed all manner of unsightly experiments on it. In a classic monster movie, this is well-tread territory, expected and accepted. We rightfully fear the unknown, flee its grasp.

Doug Jones portrays a mysterious aquatic creature, and Sally Hawkins is a protagonist who befriends him in the Guillermo del Toro film “The Shape of Water.” (photo courtesy of Fox Searchlight Pictures. © 2017 Twentieth Century Fox Film Corporation All Rights Reserved)

“The Shape of Water” begins with that anxiety, set in Cold War-era Baltimore. But in place of a savage beast, an indiscriminate killer, we meet something unknown but far from evil. Deep in the bowels of a research facility, janitor Elisa (Sally Hawkins) befriends what Agent Strickland (Michael Shannon) considers the military’s top asset, an amphibious creature (played by Doug Jones) captured in South America.

Little is known about the creature’s origin, but he’s strong and capable of living under water and above for a time. Strickland perceives him as a beast to be studied and discarded, but Elisa, who cleans the entire secret base alongside friend Zelda (Octavia Spencer), connects with him and forms a unique bond through sign language, since an unknown accident rendered her mute as a child.

No director has done more for the fantasy genre than del Toro (yeah, yeah, Peter Jackson is awesome, but del Toro is brilliant). From early films like “Cronos” to the 2006 masterpiece “Pan’s Labyrinth,” he infuses new life into a genre often criticized for simplistic depictions of good and evil. Even in “Hellboy II: The Golden Army,” a fantasy superhero film, we experience a captivating story featuring elven royalty, trolls, gods and even the Angel of Death.

Perhaps most notable, the creature in “The Shape of Water” looks quite a bit like Abe Sapien, another amphibious creature in the “Hellboy” films. In place of CGI, both creatures come to life with the help of complex costuming, thanks to designer Luis Sequeira, who previously worked on two other del Toro productions: FX series “The Strain” and 2013’s “Mama.” His work here is incredible, a tribute to a part of cinema history that hopefully won’t be replaced by the ones and zeros of a computer.

But none of this is possible without del Toro’s No. 1 collaborator, someone the director casts more than Ron Perlman. And very few people know who he is. I give you Doug Jones (no, not Roy Moore’s opponent). Jones is a body actor who uses his background as a mime and contortionist to land multiple roles a year as the basis for CGI characters and the monster in horror films. In “Hellboy II,” he plays three characters. In “Pan’s,” he’s the fawn and the Pale Man whose eyeballs reside in each hand, not his face. He’s played demons on “Buffy the Vampire Slayer,” the body of superhero the Silver Surfer and lately Saru, the first officer on “Star Trek: Discovery.”

Jones plays a lot of monsters and inhuman characters, but his performance in “The Shape of Water” is something special. Rather than evoke terror, this aquaman is equally misunderstood and mysterious. But neither means he’s cuddly; he responds to violence in kind. And the human world is a marvel he doesn’t fear but curiously embraces. The challenge for Jones is delivering all these complexities in a head-to-toe costume that only allows him to move his mouth and limbs. He doesn’t even have access to his eyes, which blink with the aid of a mechanical device.

Michael Shannon stars as Agent Richard Strickland, and Michael Stuhlbarg portrays Dr. Robert Hoffstetler in “The Shape of Water,” an adult fairy tale set during the Cold War. (photo by Kerry Hayes. © 2017 Twentieth Century Fox Film Corporation All Rights Reserved)

And then there’s Hawkins, as Elisa. Like Jones’ performance, she tells her story visually, without the aid of dialogue. Certainly, this is offset to a degree by her neighbor and best friend, Giles (Richard Jenkins), who speaks enough for both of them, but Hawkins’ character is far from just a narrative necessity. Her evolution matters just as much as whatever Darwinian event created her water-dwelling counterpart.

As a period piece, del Toro’s “The Shape of Water” is a delightful exploration of a time riddled with nationality at the expense of rational thought. But this film isn’t just one thing. That’s the del Toro way: genre merging that fractures expectations. And he does this with great ease through incredible performances and production unlike anything else.