Casualty newcomer Matty Linlaker will find himself in a dangerous situation tomorrow, when a training exercise goes horribly wrong. The self-assured doctor decides to ignore safety instructions, leaving him vulnerable t0 a potentially deadly pathogen.

Last month, Holby ED faced a spot inspection from the CQC, following an anonymous report by Matty. The disastrous visit meant a full inspection was ordered to decide the fate of the department.

In this week’s episode, Flynn is determined to prove the ED’s competence to the CQC, by arranging a training simulation for Matty and Dr Kim Chang. Dr Grace Clements, an expert in dangerous pathogens, arrives to play the role of ‘patient zero’ in an encephalitis breakout.

The residents are told they must complete the exercise as if it is real. However, Matty argues that the PPE is out of date and refuses to secure his properly. Meanwhile, anxious Kim notices that Grace is tachycardic with a very high temperature, but the latter assures her that she’s just under the weather.

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Later, Grace is suddenly overwhelmed by a coughing fit, with blood leaking from her nose and eyes. She reveals she may have been exposed to a pathogen, but refuses to divulge information regarding her work with the Ministry of Defence.

Having chosen not to wear his PPE correctly, Matty is left unprotected when Grace’s blood spatters all over his face. He frantically asks Kim to help diagnose Grace’s symptoms to determine the pathogen he has now been exposed to.

Flynn soon takes over the situation and instructs the residents on their next steps. He assures them that the date on the protective gear is precautionary, but is appalled to discover that Matty wasn’t wearing his properly.

Elsewhere, Dylan admits to Stevie that he was wrong for taking Matty’s DNA in order to confirm his paternity. However, he laments about missing his son’s childhood while being kept in the dark by Matty’s mum.

Later, Dylan’s heart sinks when hears that Matty has been exposed to an unidentified pathogen. Will he lose his son before he is able to get to know him?