K'nuckles, Flapjack, and Bubbie are planning to flee as Low Tides Day approaches, due to the tide being too low for Bubbie to survive. But Flapjack convinces Bubbie to leave him and K'nuckles behind so he can celebrate Low Tides Day, much to K'nuckles's horror. K'nuckles reveals that when he was a little boy, his mother told him about how every year on Low Tides Day, people would hang their boots in the water, and the next day they'd find a present in them. He did exactly that, but the next day his boot was empty. He was then sacked by 6 to 8 mermen for being a bad boy.
After telling K'nuckles the story, K'nuckles attempts to hide in his hidey-hole, but it's already occupied. He runs through the town, desperate to find a hidey-hole. But all the hidey-holes in the entire town are filled. In order to avoid being sacked, K'nuckles must be a good person so he can get a present in his boot. Flapjack convinces him to apologize to Peppermint Larry for shoving him off a ladder. He does so, but Peppermint Larry overhears him revealing that his apology was insincere. As revenge, he gives him a cookie shaped like a merman.
After Flapjack and Candy Wife are instructed to cover their ears, the K'nuckles and Peppermint Larry begin swearing at each other. Then Flapjack and K'nuckles come up with another plan: They decide to appear in the town's holiday pageant as replacements to help a little boy named Peter. Unfortunately, during a scene where K'nuckles's character is supposed to be sacked by Mermen, he goes berserk, ruining the entire play. Afterward, he doesn't seem to realize what he did and is looking forward to getting a present.
The next day, K'nuckles finds his boot empty and the mermen are ready to sack him. But Flapjack discovers a hole in K'nuckle's boot and thinks that the captain's present must have fallen to the ocean floor. For this reason, he throws K'nuckles and himself off the deck. They survive, using Lolly's buckets as parachutes. K'nuckles's flees from the mermen who, having no legs, at first struggle greatly to move on land but eventually link their tails and bodies together to form a bipedal humanoid tower (in a parody of combining mechas) and gives chase. Meanwhile Flapjack goes looking for the present, picking up everything he can find. But the tide begins to come back in before he can even finish his song. However, he convinces Poseidon to keep the tide out a little longer. Meanwhile, Bubbie returns at her normal time but discovers that the tide is still out. K'nuckles begins helping her by splashing water on her, albeit not on purpose at first. He then convinces the mermen to help instead of trying to sack him.
The mermen end up tied up by all of the so-called "bad people" in town, who have come out of their hidey-holes. Poseidon appears to stop the people from sacking them. He asks Flapjack why he has a giant sack, and Flapjack replies that he was going to give the presents in the sack to all the people who didn't get presents. Upon hearing this, Poseidon declares that from now one, sacks will only be used for storing gifts, delivered by Peppermint Larry, while people may but smaller gifts in boots. The episode ends with K'nuckles choosing the hidey-hole over Bubbie's respect.
- Low Tidings was orginally titled, "Flapjack's Home for the Holidays".
- This is seventh time we saw a kid version of K'nuckles from the past first and second seasons.
- This is the first two-part episode
- This is the second time mermen appeared. The first time was in Gone Wishin'
- The mermen were shown to be unable to chase Flapjack and K'nuckles on land (hence needing to link together to a humanoid formation) yet when they move toward the end of the pier and later when they come to help Bubbie, they are shown squirming on their tails.
- Poseidon's two children (and presumably Poseidon himself) are similarly able to slither on their tails in an upright position.
- It is proven that this show takes place hundreds of years in the past, since at the end of this episode, Poseidon anounced that Low Tides day shall now be Christmas.