Movie studio estimates showed the civil rights-era story about the racial divide between white women in Mississippi and the black women who worked for them had taken in $14.2 million over three days ending on Sunday and appeared headed toward $18 million by Monday, the US Labor Day holiday.

The movie, backed by DreamWorks and released by the film division of The Walt Disney Co, topped No. 2 film, spy thriller “The Debt,” which collected $9.7 million through Sunday and was poised for an $11.6 million haul by Monday, according to industry watcher Hollywood.com Box Office.

“The Debt,” a newcomer to theaters from Focus Features, raked in an average of $5,300 per theater from 1,800 venues through Sunday. It is expected have sold $14 million worth of tickets in domestic — US and Canadian — theaters by the time the holiday ends on Monday.

Taking the No. 3 spot was another new movie, space alien mystery “Apollo 18,” which purports to use “found footage” of an ill-fated trip to the moon to tell its otherworldly tale. It had taken in $8.7 million, or $2,600 per venue, for the three days ending on Sunday. A Monday forecast was not available for the movie released by privately held Weinstein Co.

Close behind was the weekend’s third new release, another thriller, “Shark Night (3-D).” It was seen collecting $8.6 million through Sunday and adding $1.9 million on Monday, to end at $10.5 million, according to its studio, closely held Relativity Media. For the three days ending on Sunday, its average was estimated at $3,000 per venue.