Brave Witches - Season 1 Episode 5 Deadly Battle in the Freezing Cold

Shimohara, Georgette and Hikari are out on patrol when they find the whole lake near the base has frozen over! It's an ice Neuroi! They engage the enemy, but it's too cold, and freezes their units solid. The Neuroi then proceeds to freeze the entire base! With no one else able to launch, it's up to the three of them to take out this frozen foe.