Sunday night's Animal Planet special showed video of purported mermaid sightings and featured an exclusive interview with a man described as a former scientist with the National Oceanic and Atmospheric Administration (NOAA).
Only the scientist was an actor and the show ended with a disclaimer implying the whole special was a hoax.
"Though certain events in this film are fictional, Navy sonar tests have been directly implicated in whale beachings," the disclaimer read.
That disclaimer, however, appeared only at the tail-end of the special, in a blink-and-you-miss-it moment.
"We wanted people to approach the story with a sense of possibility and a sense of wonder," the show's executive producer, Charlie Foley, told ABC News. "Hopefully that's what 'Mermaids' allowed viewers to do&.allowed them to suspend their disbelief."
When the original "Mermaids" ran last year, NOAA was forced to put out a statement on its website that mermaids were not, in fact, real.
"No evidence of aquatic humanoids has ever been found," the statement read.
Despite the lack of evidence, the major ratings win has Animal Planet mulling what else can be done on "Mermaids."
"It has us thinking about what we do next," Animal Planet General Manager Marjorie Kaplan told the Washington Post's TV Column. "We're thinking big."