  One of the simplest pseudo-Hermitian models with real spectrum (viz.,
square-well on a real interval I of coordinates) is re-examined. A PT-symmetric
complex deformation C of I is introduced and shown tractable via an innovated
approach to matching conditions. The result is surprising: an arbitrarily small
deformation I -> C implies a sudden collapse (i.e., the spontaneous PT-symmetry
breaking) of virtually all the spectrum (i.e., up to its low-energy part).
