  The Magellanic Stream (MS) is the nearest example of a gaseous trail formed
by interacting galaxies. While the substantial gas masses in these kinds of
circumgalactic structures are postulated to represent important sources of fuel
for future star formation, the mechanisms whereby this material might be
accreted back into galaxies remain unclear. Recent neutral hydrogen (HI)
observations have demonstrated that the northern portion of the MS, which
probably has been interacting with the Milky Way's hot gaseous halo for close
to 1000~Myr, has a larger spatial extent than previously recognized, while also
containing significant amounts of small-scale structure. After a brief
consideration of the large-scale kinematics of the MS as traced by the
recently-discovered extension of the MS, we explore the aging process of the MS
gas through the operation of various hydrodynamic instabilities and
interstellar turbulence. This in turn leads to consideration of processes
whereby MS material survives as cool gas, and yet also evidently fails to form
stars. Parallels between the MS and extragalactic tidal features are briefly
discussed with an emphasis on steps toward establishing what the MS reveals
about the critical role of local processes in determining the evolution of
these kinds of systems.
