When a 100,000-guilder contest is announced in 1800s Holland, Cornelius sets about to grow one to win the prize. However, at the same time, the local alchemist, Boxtell, is trying to cast a spell that will give him unlimited power - and 2 of his ingredients must be a fair maiden (Corneliuss girlfriend, Rosa) and a black tulip. Cornelius succeeds in producing a black tulip, but is then arrested for treason for possessing something sent him in the mail - and Boxtell steals his tulip. Cornelius must escape from jail, retrieve his precious flower, and stop Boxtell from completing his spell.