  We explain microscopically why split attractor flows, known to underlie
certain stationary BPS solutions of four dimensional N=2 supergravity, are the
relevant data to describe wrapped D-branes in Calabi-Yau compactifications of
type II string theory. We work entirely in the context of the classical
geometry of A-branes, i.e. special Lagrangian submanifolds, avoiding both the
use of homological algebra and explicit constructions of special Lagrangians.
Our results provide a way to disassemble and assemble arbitrary special
Lagrangians to and from more simple building blocks, giving a concrete way to
determine for example marginal stability walls and deformation moduli spaces.
