  The coalescence of droplets plays a crucial role in nature and modern
technology. Various experimental and theoretical studies explored droplet
dynamics in 3D and on 2D solid or liquid substrates. In this paper, we
demonstrate the coalescence of isotropic droplets confined in thin quasi-2D
liquids -- overheated smectic films. We observe the merging of micrometer-sized
flat droplets using high-speed-imaging and analyse the shape transformations of
the droplets on the timescale of milliseconds. Our studies reveal the scaling
laws of the coalescence time, which exhibits a different dependence on the
droplet geometry than in case of droplets on a solid substrate. A theoretical
model is proposed to explain the difference in behaviour.
