In the end, everyone was wrong.

With "Don't Breathe" and "Suicide Squad" maintaining their death grips on the top two slots at the box office, the slugfest this Labor Day weekend was for third place, and it was anybody's guess which of the two new wide releases -- prestige weepie "The Light Between Oceans" and sci-fi chiller "Morgan" -- would win the competition for the bronze medal.

In this corner: "Light," aiming to land the first major blows of Oscar season. Based on a popular recent novel, armed with an Academy Award-caliber cast (two winning actresses and a twice-nominated actor), a tearjerking child-custody premise, and a 1,500-screen release. Predictions ranged from $5 to $8 million -- not great numbers, to be sure, but Labor Day weekend is traditionally a box-office desert.

And in the opposite corner: "Morgan," a low-budget Frankenstein tale about a genetic experiment gone awry, evoking such similar recent movies as "Ex Machina" and "Splice." It's from the house of Ridley Scott, director of visionary and popular sci-fi films from "Alien" to "The Martian," though he only produced the film; the director is his son, rookie filmmaker Luke Scott. The cast has some familiar and respected names. Opening on 2,020 screens, "Morgan" was predicted to earn between $5.5 and $8 million.

Some pundits gave "Morgan" the edge since it was opening on 520 more screens than "Light," and since Labor Day weekend is a traditionally friendly time for scary movies. Others gave it to "Light," given the prestige factor and it's more positive reviews and word-of-mouth.

What no one predicted, however, was that both films would underperform even those modest predictions, and that neither would even crack the top five. Sunday estimates had "Light" debuting in sixth place with just a hair ($16,000) under $5 million. Still, that was a lot better than "Morgan," which premiered way down at No. 17 with just an estimated $1.96 million.

What went wrong? Here are a few things.

The Holiday. Of all the year's holiday weekends, Labor Day is traditionally the worst at the box office, maybe because everyone's either on the road or firing up the backyard grill one last time. Indeed, it wasn't just the two new movies that suffered this weekend. Box office as a whole was down 17 percent from last weekend and fell below $100 million for the first time in seven months. Almost makes you wonder why anyone would bother releasing a new movie at all this weekend.

The Competition. Over the past 15 years, Labor Day has been kinder to horror films than other genres. That should have helped "Morgan," except that it had to compete against the still-popular "Don't Breathe," which stunned with a $26.4 million first-place debut last week and fell just 40 percent this weekend (not including Monday's take) to an estimated $15.7 million. The rest of the top five movies ("Suicide Squad" in second, followed by "Pete's Dragon," "Kubo and the Two Strings," and "Sausage Party") also held up surprisingly well, losing just 13 to 30 percent each of the previous weekend's business, even though they've all been in theaters for three to five weekends already.As for "Light," it was competing for a predominantly female audience against "Don't Breathe" and even "Bad Moms," which, though it's an R-rated comedy that's been out for six weeks, is also holding up well. It came in seventh with an estimated $4.7 million, down just 15 percent from a week ago and only $244,000 shy of "Light." In fact, when the final holiday weekend numbers are released on Tuesday, "Moms" could come out ahead of the newcomer.

The Reviews. An Oscar-bait movie like "Light" and a philosophical sci-fi movie like "Morgan" both depend a great deal on support from the critics. Unfortunately, they had mixed feelings about the melodrama, giving it a modest 61 percent fresh rating at Rotten Tomatoes. Still, that's much better than "Morgan," which earned just a 43 percent score.

The Word-of-Mouth. Judging by the grades at CinemaScore, audiences pretty much agreed with the critics on both films. They gave "Light" a B+, which is just a so-so grade at CinemaScore, and "Morgan" a C+, which is dismal. So it's not likely that ticketbuyers strongly recommended either movie to their friends.

The Casting. Yes, Michael Fassbender is an "X-Men" franchise star with two Oscar nominations to his credit, Alicia Vikander is a rising star who won her first Oscar earlier this year, and Rachel Weisz is a past Oscar-winner, too. Yet not even the real-life romance that flourished between Fassbender and Vikander on the "Light" set was enough to sell the movie. None of these performers is a proven box office draw on his or her own, and none of them is a big enough name to overcome the movie's less-than-ideal reviews or word-of-mouth.Similarly, "Morgan" stars Kate Mara, Jennifer Jason Leigh, and Paul Giamatti are all acclaimed actors who've done well in ensemble casts; Michelle Yeoh is a big star in Asia with modest name recognition here, and young Anya Taylor-Joy (who plays the title character in "Morgan") made a big splash earlier this year in minor horror hit "The Witch." But again, none of these actors sell tickets in North America on their own.

The Age Factor. Prestige dramas tend to skew toward older audiences, but "Light," despite its PG-13 rating, seemed to go out of its way to spurn younger viewers. According to distributor Disney, the audience for the movie was 92 percent over the age of 25 and 44 percent over the age of 50. Oh, and 0 percent under 17. "Morgan," with a predominantly older cast, an R-rating for graphic violence, and a food-for-thought premise, also kept young viewers away. Of course, family audiences were busy watching "Pete's Dragon" and "Kubo" anyway.

The Wild Cards. Horror films aren't the only movies that have done unexpectedly well around Labor Day. So have Mexican imports, at least ever since Lionsgate's "Instructions Not Included" exploded at this time three years ago. This weekend, the distributor released Mexican comedy "No Manches Frida" on just 362 screens, but it pulled in an estimated $3.7 million, good for a 12th place debut and a mighty per-screen average of $10,083. That's about twice what "Don't Breathe" earned per theater, three times what "Light" averaged, and 11 times what "Morgan" averaged.

But that wasn't the only surprise rival for this week's new wide releases. Several films that have been out for months added to their theater counts this weekend, hoping to squeeze the last few drops of summer enthusiasm from ticketbuyers. "Finding Dory" and ""Ghostbusters," both playing on only about 300 screens last week, expanded wide to more than 2,000 and more than 1,000 theaters, respectively, resulting in an additional $2 million or so for the 12-week-old "Dory" and about another $1 million for eight-week-old "Ghostbusters." "Ice Age: Collision Course," "Nerve," "Don't Think Twice," "Hillary's America," and "Independence Day: Resurgence," all of them at least six weeks old and sinking at the box office a week ago, all added screens this weekend and saw their sales increase over last week.

It's not all bad news for "Light" and "Morgan." Both movies were fairly cheap to make ("Light" cost a reported $20 million, "Morgan" just $8 million), and when overseas grosses come in, they should both at least break even. Still, returns like those are the reason Hollywood studios focus on sprawling action blockbusters instead of contemplative movies for grown-ups.