  We report on the first direct in situ measurements of a fast coronal mass
ejection (CME) and shock in the corona, which occurred on 2022 September 5. In
situ measurements from the Parker Solar Probe (PSP) spacecraft near perihelion
suggest two shocks with the second one decayed, which is consistent with more
than one eruptions in coronagraph images. Despite a flank crossing, the
measurements indicate unique features of the young ejecta: a plasma much hotter
than the ambient medium suggestive of a hot solar source, and a large plasma
$\beta$ implying a highly non-force-free state and the importance of thermal
pressure gradient for CME acceleration and expansion. Reconstruction of the
global coronal magnetic fields shows a long-duration change in the heliospheric
current sheet (HCS), and the observed field polarity reversals agree with a
more warped HCS configuration. Reconnection signatures are observed inside an
HCS crossing as deep as the sonic critical point. As the reconnection occurs in
the sub-Alfv\'enic wind, the reconnected flux sunward of the reconnection site
can close back to the Sun, which helps balance magnetic flux in the
heliosphere. The nature of the sub-Alfv\'enic wind after the HCS crossing as a
low Mach-number boundary layer (LMBL) leads to in situ measurements of the near
subsonic plasma at a surprisingly large distance. Specifically, an LMBL may
provide favorable conditions for the crossings of the sonic critical point in
addition to the Alfv\'en surface.
