Rule reminder
In formal and literary Italian, modal clauses often use: 'quasi' + subjunctive (compact form), 'quasi che' + subjunctive (connective form), 'come se' + subjunctive (standard), and gerundio for manner. The indicative is never used after 'come se', 'quasi', or 'quasi che'.
Il protagonista taceva, ___ le parole si fossero esaurite dentro di lui.