When did Snape's spying career begin?

[meglet2]

No: HPFGUIDX 36181

--- In HPforGrownups at y..., "dicentra_spectabilis_alba" <bonnie at n...> 
wrote:
> > 
> Whoa!  Hold the phones.  Somebody check GoF again.  (I've only got 
PoA
> with me today.) Does it *say* that Snape was a DE who turned or 
does
> it only say that he was a spy?  What if he never was a DE?  That 
would
> be interesting.
> 
> --Dicentra, noting that it would mean the demise of George and his
> sister Diana and many other interesting theories.

Don't panic. We are very definitely told that Snape was a DE. GoF 
Ch. 30, 'The Pensieve' (p.513 UK edition), Dumbledore 
speaking. 'Severus Snape was indeed a Death Eater. However, he 
rejoined our side before Lord Voldemort's downfall and turned spy 
for us, at great personal risk. He is now no more a Death Eater than 
I am.' 

I am sure that it is only my horribly twisted and suspicious mind 
that has occasionally wondered if that last sentence could possible 
conceal an ironic double meaning. You know, the evil Dumbledore 
thing which I mostly resist believing in.

Mercia