  We consider the dynamics of an equatorial explosion powered by a millisecond
magnetar formed from the core collapse of a massive star. We study whether
these outflows -- generated by a priori magneto-centrifugally-driven,
relativistic magnetar winds -- might be powerful enough to produce an
ultra-relativistic blade ("lamina") that successfully carves its way through
the dense stellar interior. We present high-resolution numerical
special-relativistic hydrodynamic simulations of axisymmetric
centrifugally-driven explosions inside a star and follow the blast wave
propagation just after breakout. We estimate the engine requirements to produce
ultra-relativistic lamina jets and comment on the physicality of the parameters
considered. We find that sufficiently collimated -- half-opening angle
$\theta_r \leq 0.2^\circ$ -- laminas successfully break out of a compact
progenitor at ultra-relativistic velocities ($\Gamma_{\rm core} \gtrsim 30$)
and extreme isotropic energies ($E_{k,\rm iso} \sim 5 \times
10^{52}\text{erg}$) within a few percent of the typical spin-down period for a
millisecond magnetar. The various phases of these ultra-thin outflows such as
collimation shocks, Kelvin-Helmholtz instabilities, and lifetime are discussed
and we speculate on the observational signatures echoed by this outflow
geometry.
