  We study the Ruderman-Kittle-Kasuya-Yosida (RKKY) interaction in a monolayer
MoS$_2$. We show that the rotation of the itinerant electron spin due to the
spin-orbit coupling causes a twisted interaction between two magnetic adatoms
which consists of different RKKY coupling terms, the Heisenberg,
Dzyaloshinsky-Moriya and Ising interactions. We find that the interaction terms
are very sensitive to the Fermi energy values and change dramatically from
doped to undoped systems. A finite doping causes that all parts of the
interaction oscillate with the distance of two magnetic impurities, $R$ and the
interaction behaves like $R^{-2}$ for the long distance between two localized
spins. We explore a beating pattern of oscillations of the RKKY interaction
which occurs for the doped system.
