Warriors in Winter by Mary Pope Osborne

Jack and Annie travel to Roman-occupied Britain, where they meet a young girl training to be a warrior in a Celtic tribe. Amid snowy forests and looming danger, they help her protect her village from Roman soldiers. To complete their task, they must prove themselves as brave and wise allies. The plot is filled with tension, winter survival, and ancient tradition. It’s a thrilling and respectful look at a lesser-known chapter of history.