  Given a circulant matrix $\mathrm{circ}(c,a,0,0,...,0,a)$, $a\ne 0$, of
order~$n$, we ``border'' it from left and from above by constant column and
row, respectively, and we set the left top entry to be $-nc$. This way we get
a~particular title object, an example of what we call an \textit{abc matrix\/},
or an \textit{arrow-bordered circulant (matrix)\/}. We find its eigenpairs and
we discuss its spectrum with stress on extreme eigenvalues and their bounds. At
last we notice its relation to a~weighted wheel graph
