The grunt who took the thing from the power plant in SoulSilver, where does he go after you catch him in the cerulean city gym? The guy said he went to the Cape, but what is that and where is it?
The Cape is Route 24 and 25 you'll find him quite easily he's on the yellow bridge hiding between two People then he'll battle you.
Source:Hg and Ss Guide
Hope I helped.