There’s an almost magical acting moment early in the haunted house thriller “Abandoned.” It’s a scene in which new mom Emma Roberts, playing a new mom with post-partum depression that’s keeping her from bonding with her baby.

She picks the toddler up and regards him, and he regards her. There’s a mutual curiosity in what turns into something of a stare-down. You can feel a bit of “What am I missing here?” in her eyes as baby Liam gawks back with whatever emotion you want to read into a baby’s eyes. Sure, it’s almost certainly a happy accident on the set, but working with babies, you take what you can get.

Whatever subtlety Roberts brings to that moment, and a few others, are essentially wasted in this tepid tale of a young city couple — John Gallagher Jr. plays the husband — who ignore the warning signs and make their “escape to the country” in a house full of red flags.

I mean, how many real estate agents would keep the place’s ugly “murder suicide” history in mind, and even have the crime-scene photos on hand when she’s asked that question they all hate answering (honestly)?

“Why’s it been on the market so long?”

Sara’s “I don’t mind a little haunting” isn’t exactly what we’d expect her to say. But this house and its history, and the creepy neighbor (Michael Shannon) next door, are sure to harsh her “change of scenery” mellow.

Only it doesn’t. Not really. Roberts’ mother is meant to lose her wits, not knowing if she’s seeing things that cannot be, if she will never connect with her baby before whoever or whatever’s in this house threatens that baby or takes little Liam away.

Roberts doesn’t make that journey as an actress. Any suspense, rising sense of terror and manic reaction to her veterinarian husband’s underreaction to the house’s shenanigans and over-reaction to her disinterested mothering, is missing.

Horror movie acting is a particular skill, an Oh-MY-GOD buy-in that she’s got to accept before we buy in to her in this role and by extension, this movie. Roberts shows no sign of having that skillset.

The Erik Patterson and Jessica Scott script is laughably generic, and even the potentially alarming moments are given a cut-rate handling by director Spencer Squire, who hopefully resented the fact that the production didn’t even have money for spectral effects.

The “ghosts” are just actors in a little more makeup than the leading lady, who never convinces us she’s that scared of them or anything going on in this not-exactly-“Abandoned” house.

Is that meant to be a pun, Mom abandoning her kid? I don’t know, any more than I can make heads or tales out of bland husband Alex’s pig farmer client concerns, a subtext that doesn’t have enough correlation to what’s going on at home to merit inclusion.

An interesting cameo by Paul Schneider, as a psychotherapist who makes house calls, might be the movie’s “tell.”

The character seems annoyed at being there, quick to judge Sara and quicker to suggest medication.

Is he talking to her, or to us?

Cast: Emma Roberts, John Gallagher Jr., Paul Schneider and Michael Shannon.

Credits: Directed by Spencer Squire, scripted by Erik Patterson and Jessica Scott. A Vertical release.

Running time: 1:41