deceit - sirius black

"you'd like me to date your son?" she asked, demandingly.
"not exactly.. he will think so, but all you have to do is pretend to be interested."
"eventually," voldemort took over, his voice alone enough to make several of the group flinch, "mr and mrs black intend for sirius to join us here. you can help with that too, if necessary, but the most crucial factor is getting him back to his dear parents."
"i'd be delighted to help you."

~deceit~
in which sabrina wraith is asked by the dark lord to help return a boy to the care of his parents
or
in which sirius black unknowingly helps sabrina wraith realise that the dark lord's ways are not the right ones

[capitals used in book}