There are two cards that begin this storyline; one with a fate-locked option, and one only Seekers of the Name will see. Needless to say, here there be spoilers.
Starting The Search
Where's my soul?
Unlocks: 1 x Your very own Infernal Contract
Yes. Well. You appear to have parted with your soul. Perhaps you encountered a particularly persuasive devil. Perhaps you simply needed the money. In any case, if you're missing it at all, you might think about looking for it?
No, you're quite content, thanks
All those emotions are so much less troublesome now. Love, guilt, joy, misery, inconvenient things like that.
Unlocks: 15 x Fate
People do go on so about souls. Perhaps you shouldn't have let yours go so easily. [Even if you don't retrieve it, the chase may be diverting.]
Your soul is gone. What is left?
Unlocks: 40 x Rostygold
Distract yourself with the grape, the hop, the flushed cheek.
The Soul and the Number
The un-winds have aligned tonight. You will know the number. Your soul will carry its weight. Black and curling as fire-touched paper.
Unlocks: Seeking Mr Eaten's Name 7, 0 x Your very own Infernal Contract
Coughed up some bones on your shiny spats!
The Starveling Cat shakes and spasms, coughing up a ball of rat bones on your shoes. It speaks. 'Tonight. Snuff the lights. All the laudanum you can drink and more. Then you'll learn a thing about souls.' [Don't do this. This is even less wise than it sounds.]
Unlocks: 1 x Starveling Cat, 5 x F.F. Gebrandt's Superior Laudanum.
So where did you last see your soul?
Always start looking for something in the last place you remember having it.
An Affectionate Devil's got it
You were charmed into letting him have it, perhaps?
A Quiet Deviless took it
Did she coerce or seduce you into giving it up?
A door-to-door devil bought it
For a rather insultingly low price, too, if you remember rightly.
That vile beast took it
Is the Starveling Cat helping you to find the name? Or is it up to some terrible scheme of its own?
Unlocks: Seeking Mr Eaten's Name 7, 1 x Stain on your Soul