  Most topological insulators discovered today in spinful systems can be
transformed from topological semimetals (TSMs) with vanishing bulk gap via
introducing the spin-orbit coupling (SOC), which manifests the intrinsic links
between the gapped TI phases and the gapless TSMs. Recently, we have proposed a
new family of TSMs in time-reversal invariant {\it spinless} systems, which
host butterfly-like nodal-lines (NLs) consisting of a pair of identical
concentric intersecting coplanar ellipses (CICE). In this Communication, we
unveil the intrinsic link between this exotic class of nodal-line semimetals
(NLSMs) and a $\mathbb{Z}_{4}$ = 2 topological crystalline insulator (TCI), by
including substantial SOC. We demonstrate that in three space groups ({\it
i.e.} $Pbam$ (No.55), $P4/mbm$ (No.127) and $P4_2/mbc$ (No.135)), the TCI
supports a fourfold Dirac fermion on the (001) surface protected by two glide
symmetries, which originates from the intertwined drumhead surface states of
the CICE NLs. The higher order topology is further demonstrated by the
emergence of one-dimensional helical hinge states, indicating a new higher
order topological insulator protected by a glide symmetry.
