Alistair Grim's Odd Aquaticum

As Grubb and Alistair Grim are beginning to form their father and son bond, they must do so in secret as the whole of London is convinced that Grim is a mad sorcerer. There’s a bounty on his head and everyone is on the lookout for the telltale sparkling green smoke of the Odditorium. But the Grims won’t stay in one place for long. Alistair has a plan to reveal the true evil magician.

Grim is determined to find and defeat Prince Nightshade and find the elusive Excalibur,King Arthur’s sword in Avalon, which contains very powerful magic. More powerful than any Odditoria he could find. Along with the rest of the crew: Grubb, Mack, Cleona, Lord Dreary, Mrs. Pinch, and Nigel, Grimm enlists his old best friend, Oscar Bricklewick, an extremely intelligent but prickly professor to come along.

In true Alistair Grim fashion, the journey to Avalon is a little out of the ordinary. As it turns out the house of mechanical wonders cannot only fly; it can swim too! They batten down the hatches and set off underwater. But it’s not all smooth sailing. Almost immediately, they come face to face with a witch called Mad Malmuirie and learn that Prince Nighshade is after the Excalibur too.

Now it’s a race against time to reach Avalon before Nightshade, but that’s not all. The true keeper of the Excalibur is written in the Avalonian Queen’s prophecy, and Grubb begins to realize that his own destiny and that of his deceased mother might be hidden there as well.