Henry and the Guardians of the Lost is a companion novel to the Charlie Bone series. It takes place a year after the end of Charlie Bone and the Red Knight and focuses on Henry Yewbeam, the boy who was lost in time.
"The yellow letter arrived on a Saturday, otherwise Henry would have been at school. The envelope was such a bright, sunny colour, no one would have believed that it contained a bombshell.
Less than 10 minutes after the arrival of the mysterious letter, Henry is on the run with his Auntie Pearl, possibly never to return home. Henry has a secret. He is twelve, but he hasn’t aged a day since the moment he was thrust a hundred years into the future. Now his secret has put him in danger. His only hope is the protection of the Guardians of the Lost."
Henry Yewbeam has a secret: he hasn't aged a day since he first travelled through time nearly two years ago. After reuniting with his brother, he has been living safely out of the way in Ocean View with his brother's housekeeper, Pearl. One Saturday, Henry sees a yellow envelope among the mail he receives from Frank the mailman, and sees that it is from Treasure, Pearl's sister. He gives it to Pearl, who opens it and reads the letter inside. Once she does so, Pearl looks very alarmed, and tells Henry to pack his bag. Henry does so, though he is very confused. When Pearl tells him to take something he loves, he takes Enkidu, his cat.
Pearl and Henry leave Ocean View, and drive for hours, until they come to a town called Timeless. Pearl finally tells Henry what is going on: the letter from Treasure was a warning, saying that there were men who would be coming to Ocean View for Henry, because they believe that his inability to age might be the key to eternal life. Not even Pearl would have been able to stop them from taking him, so they both had to flee. In Timeless, Pearl takes Henry to a place called Martha's Cafe; shortly after, she goes into the Ladies' Cloakroom, claiming that she's going to tidy up her hair. Henry waits for her, and as time passes he begins to wonder why she's taking so long. Two children (whose names Henry later learns are Penny and Peter Reed) sitting at a table by the window notice Henry waiting, and tell Henry that they saw Pearl leave in her car. After a while, he agrees to come over to their house, 5 Ruby Drive, and wait for Pearl there.
Henry writes a note for Pearl, leaves it in the care of Martha, and walks with the two children to their home. The children's parents welcome him and Enkidu, and give him a room to sleep in for the night. Henry finds a note in his jacket pocket from Pearl, telling him to go round to the trees behind the cafe and waiting for someone called Mr Lazlo. When the man comes, he is to ask him where the white bird flies, and he must reply 'In the Little House' or it's not the right person. She also warns Henry to tell no one about it. Because of this Henry doesn't tell the Reeds about the note.
The next morning Mrs Reed asks him questions and seemingly begins to arrange for him to attend a school in the town. To Henry's horror, however, he spies henchmen (efficient guards and keepers of order) standing outside the Reeds' house and realises that they have come from him, and that he will be in danger if he stays in the Reeds' house. He escapes, and goes in search of the place his aunt wrote to him about. He stumbles upon a cockatoo, which he surmises is the 'white bird' mentioned in the note. Henry and Enkidu follow the cockatoo through a forest, to an old house called "The Littles' House". There, a strange-looking man sees Henry and asks whether he is 'a spy or a rover'.
Residents of the Littles' House