Er ei bod hi'n nos ac mae'r awyr i fod yn dywyll - mae'n rhy dywyll. Mae Gwil, Cyw a Jangl wedi drysu'n lân. Although it's night and the sky should be dark, it's too dark. What has happened?
Dydy Fflamingo ddim yn aros yn llonydd ddigon hir i'r criw ei fesur. Tybed oes ffordd arall o'i fesur? Flamingo doesn't stay still long enough to be measured. How else can they measure him?
Mae Siani Flewog, un o ffrindiau Plwmp a Deryn wedi bod ar goll ers awr, ond pa mor hir yw awr? Siani Flewog is missing. She's been gone a full hour, but how long is an hour?
Mae'n ddiwrnod cynta'r tymor yn ysgol 'Dan Dwr' ond mae un o'r disgyblion ar goll! It's the first day of the school term 'Under Water' but one of the students is missing!
Mae Llew yn poeni. Adeiladodd gastell tywod hyfryd ar y traeth ond mae wedi diflannu! Llew is upset. He built a lovely sandcastle on the beach but it has disappeared! Where has it gone?
Mae 'na lanast a hanner yng nghegin Cyw heddiw; mae gliter, glud a phaent ymhobman! There's a big mess in Cyw's kitchen today; there's glitter, glue and paint everywhere!
Taith i Begwn y Gogledd ar drywydd het, hances a hosan goll Jangl sy'n wynebu Jen a Jim. Jen and Jim are going on a trip to the North Pole to look for Jangl's hat, handkerchief and sock.
Mae Bolgi a Cyw'n poeni am un o ieir y fferm. Mae hi wedi dodwy wyau lliw indigo! Bolgi and Cyw are worried about one of the chickens on the farm. She has laid indigo coloured eggs!
Mae Jen a Jim wedi derbyn gwahoddiad gan griw Cyw i gael picnic ar y traeth. Cyw and friends have invited Jen and Jim for a picnic on the beach and they plan to do jigsaws with Jac-Do.
Mae lleidr wedi cyrraedd y fferm, ond yr unig beth mae'n ei ddwyn yw letys! There's a thief on the farm, but the only thing stolen is a lettuce! Can the friends catch the culprit?