  We discovered two small high-velocity compact clouds (HVCCs) in HCN $J=4-3$
and $J=3-2$ maps of the central 20 pc of our Galaxy. Both HVCCs have broad
velocity widths ($\Delta V \gtrsim 40$ km s$^{-1}$) and compact sizes ($d\sim
1$ pc), and originate from the dense molecular clouds in the position-velocity
space. One of them has a faint counterpart in a Paschen-$\alpha$ image. Their
spatial structure, kinematics, and absence of luminous stellar object are
compatible with the notion that each of the small HVCCs is driven by the plunge
of an invisible compact object into a molecular cloud. Such objects are most
likely inactive, isolated black holes.
