  Recent measurements revealed an anomalous Coulomb drag in graphene, hinting
at new physics at charge neutrality. The anomalous drag is explained by a new
mechanism based on energy transport, which involves interlayer energy transfer,
coupled to charge flow via lateral heat currents and thermopower. The old and
new drag mechanisms are governed by distinct physical effects, resulting in
starkly different behavior, in particular for drag magnitude and sign near
charge neutrality. The new mechanism explains the giant enhancement of drag
near charge neutrality, as well as its sign and anomalous sensitivity to
magnetic field. Under realistic conditions, energy transport dominates in a
wide temperature range, giving rise to a universal value of drag which is
essentially independent of the electron-electron interaction strength.
