 Following Ros 's death in the series eight finale , Lucas " sees the team 's been slightly shattered by it " and responds by " trying to pull the team together and aiming to be a strong figure for Harry . " The ninth series reveals a dark secret in Lucas 's past that will lead to the " ultimate betrayal . " Armitage revealed that Lucas " isn 't quite who you think he is . " It sees the introduction of a character named Maya , played by Laila Rouass , who is Lucas 's old flame and possible first love ; she is involved in Lucas 's secret . Lucas states that Maya means more to him than his job and reputation . Vaughn would use Maya as a way of controlling him . Armitage also revealed Lucas goes off the radar " quite a lot this series " and behaves " quite strangely . " 
