The Deep
Helen Dunmore
 A devastating flood has torn through the worlds of Air and Ingo, and now, deep in the ocean, a monster is stirring. Mer legend says that only those with dual blood&mdash;half Mer, half human&mdash;can overcome the Kraken that stirs in The Deep. Sapphire must return to the Deep, with the help of her friend the whale, and face this terrifying creature - and her brother Conor and Mer friend Faro will not let her go without them. Those with pure Mer blood cannot go to the Deep. Sapphire has moved back into the cottage by the cove, and is visiting Ingo all the time. When she is summoned to an assembly of the Mer she learns that the Kraken, a creature with the power to destroy their world, has awakened. Sapphire makes a deal with the Mer: if she and Conor help put the Kraken back to sleep their father will have the choice to leave Ingo. Ervys, a spokesperson(self-proclaimed leader, which the Mer do not have, as it causes problems) for the Mer, is outraged by this deal but gives his approval so the Mer will be safe. Sapphire, Conor and Faro (Faro should not be able to go to The Deep, but in Saldowr's mirror, he sees that he is not pure Mer, but part Human) go into the Deep with the help of the whale(that saves Sapphire from the Deep in The Tide Knot) to find the Kraken, and put him to sleep. It is not revealed what the Kraken really is, but it is clearly a shapeshifter. After a battle of minds, Sapphire manages to get the Kraken to sleep, and with Conor and Faro she goes back to the Mer to tell them the good news. Ervys is still furious especially when Faro asks Sapphire to make the crossing of Ingo with him. She agrees, but only on the condition that Conor may go too. Faro counters by insisting that his sister will also go. Although Sapphire does not want Elvira and Conor together, she agrees. The final chapter ends with Faro and Sapphire making Deublek, or friendship bracelets out of their hair.