  The elusive polarized microwave signal from the Fermi bubbles is disentangled
from the more extended polarized lobes, which similarly emanate from the
Galactic plane but stretch farther west of the bubbles. The ~20% synchrotron
polarization reveals magnetic fields preferentially parallel to the bubble
edges, as expected downstream of a strong shock. The ~20% polarization of
thermal dust emission is similarly oriented, constraining grain alignment in an
extreme environment. We argue that the larger lobes arise from an older
Galactic-center, likely supermassive black-hole, outburst.
