A cruel Roundhead Colonel is on the trail of royalist sympathizers, but unaware of his daughters royalist sympathies. When she falls into a love triangle with Cavalier Edward Beverly and Roundhead officer Captain Sylvester the stage is set for double crossing and derring-do.

A pirate ship, fighting in 1588 on the side of the Spanish Armada, suffers damage and must put into a village on the British coast for repairs. The village is small and isolated and the Spanish convince the villagers that the English fleet has been defeated and that they, the Spanish, are now their masters. This results in the villagers' sullen cooperation, but rumors and unrest begin to spread and soon the Spanish pirates find themselves facing a revolt.

A young man visits his fiancé's estate to discover that her wheelchair-bound scientist father has discovered a meteorite that emits mutating radiation rays that have turned the plants in his greenhouse to giants. When his own wife falls victim to this mysterious power, the old man takes it upon himself to destroy the glowing object with disastrous results.