Merck-Serono, one of the biggest Bio-Tech Company in the world, is a city-block of existing and new structures redefining convention. Opaque and transparent fragments of the building are unified by light, projecting a consistent image of strong yet soft, light yet airy, creating a magical and changing boundary to the public realm. The ultimate goal of lighting is to create a pleasant and comfortable working place for its users. Halls and bridges connecting functional areas become pleasant journeys in light and comprehension, easing, and facilitating movements. Daylight and controlled electric lighting result in a building of high technology, but low energy consumption.