It has happened to Indiana Jones and the dashing Westley in "The Princess Bride."
On Wednesday afternoon it happened to three horses in Jurupa Valley.
(Well, technically, officials are calling it wet sand, but when you're belly-deep in it, sinking, what's the difference?)
The horses had gone off trail during a two-hour ride Wednesday afternoon with their owner when they became stuck, the Riverside Press Enterprise reported.
The fast-moving sand, made of a combination of sand and water, reached the top of the three horses' bellies.
Susi Rowley told the paper that she and her 2,000-pound horse named Stretch, along with her daughter's horse and that of another woman, got stuck in the wet sand after going off established trails. They tried to go back when they got on a trail dense with overgrowth but ended up hitting a dead end. Eventually they started crossing a river channel.
"All three of us started sinking," Rowley told the Press Enterprise. "So we had to get off. We were up to our knees in spots."
They tried cajoling the horses out of the quicksand but after some movement, the panicked horses got stuck again. Rowley called her husband and some friends along with 911.
Firefighters in Riverside who showed up said the rescue mission was slow-moving.
It took 30 firefighters and specialized rigging equipment from the Norco Animal Rescue Team to pull the horses from the sand in the Santa Ana River bottom south of Limonite Avenue and Dodd Street.
By 3:50 p.m., the uninjured horses were freed and their manes were dusted off.
The Norco Animal Rescue Team is no stranger to coming to the aid of distressed equines. Norco is dubbed Horsetown USA, boasting one of the largest networks of horse trails in the United States.
In 2010, the team rescued 40 horses from rising floodwater.
Rowley told the Press Enterprise that from now on "we're going to stay on the main trail."