  In this paper we construct a new completely integrable system. This system is
an instance of a master system of differential equations in $5$ unknowns having
$3$ quartics constants of motion.We find via the Painlev\'e analysis the
principal balances of the hamiltonian field defined by the hamiltonian.
Consequently, the system in question is algebraically integrable. A careful
analysis of this system reveals an intimate rational relationship with a
special case of the well known H\'{e}non-Heiles system. The latter admits
asymptotic solutions with fractional powers in $t$ and depending on $3$ free
parameters. As a consequence, this system is algebraically completely
integrable in the generalized sense.
