Two years have passed since Sapphire first entered the amazing underwater world of Ingo. Each time she visits, she grows more and more enchanted with the sea's unending supply of colorful creatures, exciting adventures, and her friend, Faro, one of the Mer folk. However, even though she loves embracing her own Mer half, she always returns to the land, to her mom and brother, Conor.
But now she has found word on her missing father. Although he was believed by most to be dead, Sapphire and Conor always knew they would find him again, and now they have. One of the Mer had lured him back to the sea, and now they have a baby half-brother. Sapphire thinks he regrets his decision to return to the sea, but he feels he doesn't have a choice in leaving. And then an opportunity to negotiate presents itself.
The Kraken, an evil monster residing in the Deep, has awoken and now demands a sacrifice. He usually sleeps for hundreds of years at a time, leaving the Mer alone. But when he does wake up, he has the power to destroy Ingo; the Kraken is the one responsible for breaking the Tide Knot. The only way the Mer have to put him back to sleep is to offer him a boy and a girl as a sacrifice. There is one other possibility, but the Mer need help.
A long time ago, a visitor to Ingo, a human visitor like Sapphire, traveled down to the Deep and somehow put the Kraken back to sleep. The Mer can't survive the Deep. Sapphire can and has. The Mer ask Sapphire to endanger herself once again and revisit the Deep to confront the Kraken. After much thought and discussion with Conor, they decide to accept the dangerous challenge. And in return, they want their father to be given the choice to leave Ingo if he wants.
Helen Dunmore has once again created an opportunity for eager readers to venture into the wondrous world of Ingo. This third book in the series (following INGO and THE TIDE KNOT) offers even more adventure and excitement, thanks to Dunmore's vivid imagination. She weaves her words into a believable and lifelike dream, warmly inviting readers into the story, into Ingo, and allowing them to experience the journey right along with Sapphire. Near the beginning, when Sapphire has to swim and crawl through the tiny underwater cave tunnel, her fears and claustrophobia pour into readers' blood, sending shudders up and down their spine.
Dunmore is definitely an author to watch, especially since the ending of THE DEEP hints at another sequel to look forward to, involving an extensive journey for Sapphire, Conor, Faro and Elvira to the other side of the world.
--- Reviewed by Chris Shanley-Dillman