  We prove a dynamical version of the Mordell-Lang conjecture for etale
endomorphisms of quasiprojective varieties. We use p-adic methods inspired by
the work of Skolem, Mahler, and Lech, combined with methods from algebraic
geometry. As special cases of our result we obtain a new proof of the classical
Mordell-Lang conjecture for cyclic subgroups of a semiabelian variety, and we
also answer positively a question of Keeler/Rogalski/Stafford for critically
dense sequences of closed points of a Noetherian integral scheme.
