  We consider theoretical models of emission of TeV photons by Cyg X-1 during a
flare discovered by the MAGIC detector. We study acceleration of electrons to
energies sufficient for TeV emission, and find the emission site is allowed to
be close to the black hole. We then consider pair absorption in the photon
field of the central X-ray source and a surrounding accretion disc, and find
its optical depth is <1, allowing emission close to the black hole. On the
other hand, the optical depth in the stellar field is about 10 at 1 TeV.
However, the optical depth drops with increasing energy, allowing a model with
the initial energy of >3 TeV, in which photons travel far away from the star,
initiating a spatially extended pair cascade. This qualitatively explains the
observed TeV spectrum, though still not its exact shape.
