otherwise [ˈʌðəwaɪz], scour [skauə], must [mʌst]

"Would they come this far south if they lost the trail?"

"They've lost the trail, all right; otherwise they'd have been on our necks before now. Under ordinary circumstances they'd scour the woods for miles in every direction. Some of them should have passed without sight of this hill. They must be preparing to cross the river. We've got to take a chance and make for the river."

Creeping down the rocks Balthus felt his flesh crawl between his shoulders as he momentarily expected a withering blast of arrows from the green masses above them (крадясь вниз по скалам = спускаясь крадучись по скалам, Балтус почувствовал, /как/ по его телу побежали мурашки, когда он на секунду представил губительный поток стрел из зеленых масс над ними; to wither — иссушать; уничтожать). He feared that the Picts had discovered them and were lying about in ambush (он боялся, что пикты обнаружили их и лежат в засаде). But Conan was convinced no enemies were near, and the Cimmerian was right (но Конан был убежден, /что/ никаких врагов /не/ было = нет поблизости, и киммериец был прав).

momentarily [ˈməuməntərɪlɪ], ambush [ˈæmbʋʃ], enemy [ˈenɪmɪ]

Creeping down the rocks Balthus felt his flesh crawl between his shoulders as he momentarily expected a withering blast of arrows from the green masses above them. He feared that the Picts had discovered them and were lying about in ambush. But Conan was convinced no enemies were near, and the Cimmerian was right.

"We're miles to the south of the village," grunted Conan (мы /в/ милях к югу от поселка, — пробурчал Конан). "We'll hit straight through for the river (мы будем пробиваться прямо к реке). I don't know how far down the river they've spread (я не знаю, как далеко вниз по реке они распространились; to spread — распространиться). We'll hope to hit it below them (/мы/ будем надеяться, /что/ наткнемся = выйдем на нее ниже них)."