Asymptomatic nasopharyngeal carriers of Streptococcus pneumoniae can be a reservoir for severe pneumonia in children and the elderly, but there is no treatment regime that can specifically reduce the number of pneumococci without affecting the normal indigenous mucosal flora. In December 7 Science, Jutta Loeffler and colleagues from The Rockefeller University, New York, show that seconds after contact, a purified pneumococcal bacteriophage lytic enzyme (Pal) is able to kill common pneumococci, including penicillin-resistant strains.