Quicken + Flashback

[Poron]

Can I play Quicken on my opponent's turn and then Fladhback in his turn a Cabal Therapy from my graveyard simply sacrificing a creature?

Thanks

[niv]

yup

flashback is simply an alternate cost able to be paid from your graveyard. it is still considered 'casting a sorcery' when you cast cabal therapy with flashback.