Shadowhunters star Katherine McNamara has some advice before Monday nights season finale: Get a box of tissues. Get the comfort food of your choice maybe a blanket, something to cuddle with. Hold your love ones close, because its brutal.

All season long, the forces of good and evil (and wherever Sarah Hylands Seelie Queen fits in) have been waging a war over the Downworlders, supernatural beings like vampires and werewolves with part-human, part-demon souls.

Things come to a head in the final episode of the season with the threat of their extinction at the hands of big bad Valentine Morgenstern, who just so happens to be Clary Fairchilds (McNamaras character) father.

Leading up toward the end of the season, weve started to see a different side of the Shadow World. When Clary first entered it, it sort of was this world of magic and wonder and enchantment for her, McNamara told HuffPost during a Build Series interview on Monday. As shes gotten closer to taking responsibility for her actions and growing into this world and becoming more of an adult in this world, shes started to see the colder, more brutal, more deadly side of the Shadow World and that continues into this episode.