  Droplets can be levitated by their own vapour when placed onto a superheated
plate (the Leidenfrost effect). It is less known that the Leidenfrost effect
can likewise be observed over a liquid pool (superheated with respect to the
drop), which is the study case here. Emphasis is placed on an asymptotic
analysis in the limit of small evaporation numbers, which proves to be a
realistic one indeed for not so small drops. The global shapes are found to
resemble "superhydrophobic drops" that follow from the equilibrium between
capillarity and gravity. However, the morphology of the thin vapour layer
between the drop and the pool is very different from that of classical
Leidenfrost drops over a flat rigid substrate, and exhibits different scaling
laws. We determine analytical expressions for the vapour thickness as a
function of temperature and material properties, which are confirmed by
numerical solutions. Surprisingly, we show that deformability of the pool
suppresses the chimney instability of Leidenfrost drops.
