Crap, well, I can guess why :)
Untap, upkeep, Draw, attack with the Knights, Done.
Spiderman (16)
Hand: 4
Library: 46
In Play:
(U,U) Plainsx2
(U) Mt
(U) Mind Stone (T: add 1 to my mana pool. 1,T,sac ~: draw a card)
(U) Mind Stone (T: add 1 to my mana pool. 1,T,sac ~: draw a card)
(U)...