The problem was two-fold.
James and Vance (at the beach, in the fog) had seen Timmy with the bag.
And Timmy did not deny having had the bag.
But Enright wanted the bag and no one knew where it was.
Smithfield had malaria and was, therefore, useless.
And, in fact, Enright was not at all well either.
Lawrence was the only one who could help them.