  We study the simple-looking scalar integrable equation $f_{xxt} - 3(f_x f_t -
1) = 0$, which is related (in different ways) to the Novikov, Hirota-Satsuma
and Sawada-Kotera equations. For this equation we present a Lax pair, a
B\"acklund transformation, soliton and merging soliton solutions (some
exhibiting instabilities), two infinite hierarchies of conservation laws, an
infinite hierarchy of continuous symmetries, a Painlev\'e series, a scaling
reduction to a third order ODE and its Painlev\'e series, and the Hirota form
(giving further multisoliton solutions).
