  We present observations using the Baade Magellan and Canada-France-Hawaii
telescopes showing that main-belt comet 324P/La Sagra, formerly known as P/2010
R2, has become active again for the first time since originally observed to be
active in 2010-2011. The object appears point-source-like in March and April
2015 as it approached perihelion (true anomaly of ~300 deg), but was ~1 mag
brighter than expected if inactive, suggesting the presence of unresolved dust
emission. Activity was confirmed by observations of a cometary dust tail in May
and June 2015. We find an apparent net dust production rate of <0.1 kg/s during
these observations. 324P is now the fourth main-belt comet confirmed to be
recurrently active, a strong indication that its activity is driven by
sublimation. It now has the largest confirmed active range of all likely
main-belt comets, and also the most distant confirmed inbound activation point
at R~2.8 AU. Further observations during the current active period will allow
direct comparisons of activity strength with 324P's 2010 activity.
