ne

1. not (used alone to negate a verb; now chiefly with only a few particular verbs: see usage notes)
2. not, no (used before a verb, with a coordinating negative element usually following; see Usage Notes, below)
3. Used in a subordinate clause before a subjunctive verb (especially when the main verb expresses doubt or fear), to provide extra overtones of doubt or uncertainty (but not negating its verb); the so-called "pleonastic" or "expletive" ne.
4. In comparative clauses usually translated with the positive sense of the subsequent negative

pouvait

third-person singular imperfect indicative of pouvoir

donc

therefore, consequently; thus

pénétrer

1. to enter, to get in (to)
2. to penetrate
3. to see through somebody's lies or secret plans
4. to penetrate (to enter sexually; to engage in penetrative sex)