  We revisit Ekedahl, Lando, Shapiro and Vainshtein's compactification of the
stack of simply ramified covers of the projective line except for a fixed
ramification profile above infinity. In particular we draw a connection with
the Harris and Mumford stack of admissible covers showing that the boundary of
the ELSV compactification appears as a contraction of the boundary of the stack
of admissible covers. This lays the needed foundations for a combinatoral
interpretation of boundary points of the ELSV compactification
