There are several ways that a person can "go todash". One of these ways is to locate a bend of Maerlyn's Rainbow. These glasses can all send someone into another world, but Black Thirteen is the most likely to do so. Todash occurs in certain circumstances when someone dies, an experience shared by Jake Chambers and Donald Callahan. A final way to go todash is by finding the "highways in hiding" or the "todash highway". These are paths that are usually hidden to passerby, but some people, like Callahan, are called to them. They lead to worlds just next door, where only a few details are different, like Spiro Agnew or someone named Chadbourne becoming president of the United States.
Going todash is very dangerous. It is possible to get stuck between worlds in the "todash darkness", where the todash monsters dwell. It is possible to reduce this danger by keeping your destination in mind and by travelling with company.