Воины согласились было умертвить узников, чтобы кто-нибудь, выплыв, не убежал.
The soldiers planned to kill the prisoners to prevent any of them from swimming away and escaping.
The soldiers’ plan was to kill the prisoners, lest any should swim away and escape.
The soldiers’ plan was to kill the prisoners, so that none of them would swim away and escape;
The soldiers wanted to kill the prisoners to make sure they didn’t swim ashore and escape.
And the soldiers' counsel was to kill the prisoners, lest any of them should swim out, and escape.
And the soldiers’ plan was to kill the prisoners, lest any of them should swim away and escape.
And [the] counsel of the soldiers was that they should kill the prisoners, lest any one should swim off and escape.