The virus touches down on the cell like a spider landing on a balloon 1,000 times its size. It has six thin legs splayed underneath a body that resembles a syringe with a bulbous head. This is a predator named lambda, and its prey is an Escherichia coli bacterium. Having found its victim, lambda now does what uncountable trillions of viruses have done since life first emerged: it latches onto the cell membrane with its legs, attaches its syringelike part to a pore and contracts, injecting its DNA inside.