Colin the Crab, the most skillful builder on the eastern riverbank, never hesitates to help his friends. Now Colin is busy with his own new project-a garden pavilion for his home. But after a week of hard work, the pavilion of his dreams is still unfinished. Even worse, a boisterous fish family has taken over the construction site. The exhausted Colin buries himself under a blanket and refuses to open his curtains. Puzzled, Colin’s friends call an emergency meeting-it’s time for them to take action!

Karlik Krab, nejlepsi stavitel a remeslnik na celem vychodnim ricnim brehu, nikdy nevahal pomahat svym sousedum. Po dlouhem tydnu plnem prace zustava jeho vysneny modry altan stale nedokonceny, a hlucna rybi rodinka se navic uhnizdila primo na stavenisti.

Karlik, vycerpany k smrti, se zavre ve sve loznici, ulehne do postele a odmita byt jenom roztahnout zaclony a vpustit dovnitr trochu denniho svetla. Karlikovi pratele jsou zmateni. Svolavaji okamzitou poradu. Je na case aby vzali udalosti do svych rukou.