You start this one in the southeast corner. It's one of those "don't build, just roam and shoot" missions, which I don't like nearly as much as building missions. Such is life though. The whole key to this mission is to keep your medic and engineer behind the main force, and to send any guy back to the medic as soon as he's starting to get hurt. You should be able to get through this mission with no losses.

Move west, get the engineer to take over the first relay station. Go west, south, up to the bridge. Move further east now, to the second relay you could see from the ground before. Take it over too. You should be getting reinforcements as you do that. Go over a few more bridges, and you'll hit one that they blow up. No problem, put an engineer in the hut and he'll rebuild it. You'll reach a town, then go north and west. The train station (that they keep annoyingly reminding you about) is in the NW corner. Use the engineer to take it over, then hunt down the last remaining units. There's one tucked to the south of this area, make sure you take it out as well so you can get the 'mission accomplished'.

Tiberian Sun Walkthough Index