Charmed - Season 6 Episode 11 -

Paige finds herself transported back in time by a pair of Grams boots to an era of free-love and freely practiced magic where Paige really fits in. When Piper and Phoebe go back to the 1960's to rescue her they inadvertently save their grandfather whose death made Grams the warlock killing demon fighting witch they knew. In the present Leo and Chris are fighting a green gooey demon that is surrounding Halliwell Manor with out help of the Charmed Ones.