Methylene Blue can be employed as a viability indicator to determine whether cells are alive or dead. Because of its size and positive charge, it does not enter into viable cells and gets reduced to the colourless form by a reductase on the cell surface. Consequently, cells that are alive will not stain and appear colourless. In contrast, dead cells are damaged (in particular the membrane), and Methylene Blue will pass freely into them, and because they also do not contain a functioning reductase, they appear blue. In these images, I’ve used Methylene Blue to stain samples of natural pond waters to reveal both their living microbiological life and also that which has passed (the blue staining). The Methylene Blue reveals these lifeless ghosts, and their associated structures, but also highlights the integral role of these now lifeless forms, in maintaining microscopic ecologies, and the transformation of their substance into new life.