Next week on Casualty, a busy evening in the Emergency Department takes an alarming turn when a patient's injuries are revealed to have a sinister cause.

Ryan faces the biggest challenge of his career so far, while the hospital descends into chaos when the building has to be evacuated.

Here's a full collection of eight big moments coming up.

1. Donna puts the new nurses through their paces

Filled with new-found confidence in her abilities as a mentor, Donna gets strict with the new team of nurses as she warns that the Emergency Department is facing a chaotic Tuesday night.

Donna introduces four different patients who have been brought in and require close attention. Max backs her up by demanding that Ryan, Cam, Jodie and Rida bring their A-games to the busy shift ahead.

2. Tension grows between Max and Jodie

Jodie struggles to get along with her estranged dad Max as they're brought together for another shift.

When Jodie can't resist expressing displeasure over Max's behaviour, he rebukes her for backchat and brands her behaviour unprofessional.

3. Dylan makes a dangerous discovery

A homeless man is brought into the Emergency Department and appears to be delirious.

The team initially suspect that he has hypothermia, but Jodie points out that he has a mysterious wound. The situation becomes more intriguing when Dylan realises that he also has some severe burns.

The reality of the situation becomes clear as it's revealed that the man has grenades in his possession ? one of which has exploded and caused his injuries. Dylan points out the danger of the situation and tells everyone not to move.

4. The hospital is evacuated

News of the explosive devices quickly spreads around the hospital and the building has to be evacuated immediately.

As patients are rushed away, treatment tents are put up outside to ensure that everyone can still get the help they need.

Back in resus, things aren't so easily resolved as the team realises that it won't be possible to treat the homeless man outside.

Donna, Jodie and Ryan agree to stay with Dylan ? and the grenades ? while he continues to look after the patient.

5. There's a life-or-death situation for Ryan

When one of the unexploded grenades falls to the floor, Ryan instinctively catches it and averts a disaster. However, with the bottle now cracked, horror dawns on Ryan as he realises that he'll have to carry on clutching it tightly to prevent an explosion.

A bomb squad arrives at the hospital to deal with the situation, but there's no way of resolving it quickly and Ryan fears for his life as all eyes are on him. When Ryan starts to lose focus, will somebody else have to step in and take over?

6. Cam and Rida offer treatment in unique circumstances

Cam and Rida focus on helping patients in the treatment tents outside.

Both are concerned for their friends who are still in the danger zone inside the building, but they deal with the troubling situation in different ways.

7. A young patient sparks a dilemma

A young boy arrives at the hospital in a bad way after an accident outside his home.

As the new arrival needs treatment that can't be easily delivered outside, Max demands that the bomb squad allow him in the building for emergency care ? despite the obvious risks.

8. An explosion rocks the hospital

With several familiar faces still inside the building, time starts to run out before the grenade goes off.

An explosion leaves lives in jeopardy, but who will be in the danger zone?