DrStraw I'm too lazy to read all the possibiities but it seems at though T10 is an easy kill for W.
Robert Pauli: Let's put at T6, otherwise Black makes seki there. After P9 Q10 / O9 . . . it seems that Black escapes. So, White should play
at P5 and kill: Q6 Q9 . . . or P9 Q10 . . . (as bottom, yes).