  We consider a slightly subcritical branching Brownian motion with absorption,
where particles move as Brownian motions with drift $-\sqrt{2+2\varepsilon}$,
undergo dyadic fission at rate $1$, and are killed when they reach the origin.
We obtain a Yaglom type asymptotic result, showing that the long run expected
number of particles conditioned on survival grows exponentially as
$1/\sqrt{\varepsilon}$ as the process approaches criticality.
