A very powerful and dark novel for young adults that embraces the original idea of Siobhan Dowd who died before she set out to write the story. This is the story of Conor who has the same dream every night since his mother became sick. But one night, he is quite certain that there is an inhuman visitor at his window – a sort of elemental and ancient force that makes things even worse.

Nofel rymus a thywyll iawn i oedolion ifanc sy'n cwmpasu syniad gwreiddiol Siobhan Dowd a fu farw cyn iddi fynd ati i ysgrifennu'r stori. Dyma hanes Conor sydd wedi profi'r un freuddwyd yn nosweithiol ers i'w fam fynd yn sâl. Ond un noson, mae'n go sicr fod ymwelydd annynol wrth ei ffenest – rhyw fath o rym elfennol a hynafol sy'n cyffroi'r dyfroedd.