10But the barbarians for a long time knew nothing of the assistance Caesar was bringing; for he journeyed by night, bivouacking by day in very obscure places, in order that he might fall upon them as unexpectedly as possible. But they finally grew suspicious because of the excessive cheerfulness of the besieged and sent out scouts; and learning from them that Caesar was already drawing near, they set out against him, thinking to attack him while off his guard.