Summer box office could slump this weekend with only a pair of modest to mid-sized openers, Universal’s “The Purge” and Fox’s “The Internship,” added to holdovers like “Fast and Furious 6” and “Star Trek Into Darkness” beginning to wind down Stateside.

Sony is holding its breath as last weekend’s domestic flop “After Earth” launches this weekend in 60 markets including France, Italy, Russia and the U.K.

“The Purge” looks to win the weekend, with a potential low-$20 million opening, according to observers. The low-budget scarer currently has the best tracking and is outselling its competition in daily ticket sales. What’s more, horror films — more so than most other genres — tend to overperform if word-of-mouth is good.

Read Our Review of “The Purge”

“The Internship,” which stars Owen Wilson and Vince Vaughn as interns at Google, should land in the mid-teens. That would be a modest start for the $58 million film; observers note there isn’t much heat behind the PG-13-rated comedy, though it could leg out in the coming weeks.

The weekend box office has a high bar to reach, as this time last year saw a $60 million opening (“Madagascar 3”) and a $50 million-plus opening (“Prometheus”).

Among the weekend’s holdovers, “Fast and Furious 6” and Lionsgate-Summit’s “Now You See Me” look most primed to do well: “Fast and Furious” could drop between 45%-50%, putting it in the high-teens range where it would land above “The Internship.” “Fast and Furious” already crossed $500 million worldwide in three weeks.

“After Earth” should see a sizable drop domestically, down between 60% and 65%, for a pitiful weekend tally in the high-single digits. The sci-fier reached nearly $34 million through Wednesday.

“Purge” marks the first collaboration between Universal and Jason Blum’s horror shop Blumhouse Productions. The R-rated film, which stars Ethan Hawke and Lena Headey, explores a futuristic society in which all criminal activity becomes legal once a year for a 12-hour period.

Universal’s marketing campaign for the film centers on the fictional society, much like what Sony’s campaign for “District 9.” Social media chatter has remained consistently strong for “Purge.”

Meanwhile, “The Internship” will benefit from its less-restrictive PG-13 rating. Fox screened the movie  extensively to families with older kids, and it scored some of the highest-ever exit scores for a Fox comedy, according to the studio. Last weekend, Fox sneaked the film in major markets, where it drew between 75% and 80% capacity.

At the specialty box office, Roadside Attractions and Lionsgate launch Joss Whedon’s black-and-white Shakespeare adaptation, “Much Ado About Nothing,” at five locations.