  There is a growing interest in the science uniquely enabled by observations
in the MeV range, particularly in light of multi-messenger astrophysics. The
Compton Pair (ComPair) telescope, a prototype of the AMEGO Probe-class concept,
consists of four subsystems that together detect and characterize gamma rays in
the MeV regime. A double-sided strip silicon Tracker gives a precise measure of
the first Compton scatter interaction and tracks pair-conversion products. A
novel cadmium zinc telluride (CZT) detector with excellent position and energy
resolution beneath the Tracker detects the Compton-scattered photons. A thick
cesium iodide (CsI) calorimeter contains the high-energy Compton and pair
events. The instrument is surrounded by a plastic anti-coincidence (ACD)
detector to veto the cosmic-ray background. In this work, we will give an
overview of the science motivation and a description of the prototype
development and performance.
