Synopsis

In the 1580s Dr John Dee, a scholar and confidant of Elizabeth I who is known as ‘the Queen’s magician’, finds a reference to a mysterious and occult object. Fascinated, he sets out to find it and embarks on a quest that takes him 
across Europe. He eventually locates it, and discovers that it’s a rather dull looking container shaped like a bottle.
 As he learns its secrets he realises that the object is greater than it appears because it contains an imprisoned spirit with great powers. He devotes himself to learning how to engage with the god in the jar.
An emissary from the Queen tracks down Dee and summons him back to England. The country is threatened by the Spanish Armada, and the Queen looks to her magician to save it from peril. With time
 against him Dee has only one option, but it involves surrendering his find.
400 years later Amy and Jack are coming to the end of their honeymoon in
 Cornwall. Keen scuba enthusiasts, they are enjoying a last dive when Amy’s attention is caught by an object on the sea bed. She goes to retrieve it, and in doing so almost loses her life. It doesn’t take her and Jack long to realise that what they have found is no ordinary jar, and that’s when their troubles begin.
Others
 hear of their find. They want the object for their own ends and will stop at nothing to get it. Amy
 and Jack are pursued and have to survive a series of adventures 
which challenge them to their limits. Finally, in a tense
 climax, Jack and Amy are compelled to choose whether to hold on to the jar or let it go. It’s a decision which will affect the rest
 of their lives.