Sand castles
On your last legs, vision fading from pain would you be able to think straight enough to plan? Would you be able to ignore every screaming nerve and neuron to strike a deal with death itself? And then be coherent enough that'd it'd accept the offer?
Rosemary Seward made that deal in a desperate bit to save her sister and from then on she is in death of the waters' service as a psychopomp. Someone that leads the dead to the afterlife... And also hunts down those that would prevent them from eternal rest. Rosemary continues on living but how long can she stay that way when she is hellbent on tracking down the people who attacked her.