All the display elicits from the staff member I've been talking to, though, is an indulgent laugh and eye roll: "Nothing we haven't seen 100 times before," she says with blase good-humour.
It's a cold, wet afternoon in late May and we're watching the filming of a couple of scenes for this year's 90-minute Shortland Street episode. Scheduled to screen tomorrow night, it's the fourth such annual special and, as ever, the aim is to deliver something even more spectacular than what's gone before.
Given the exponential way in which the stakes have been raised each year, that's a real challenge. In 2010, the first special involved the dramatic demise of Adam Rickitt's character Kieran Mitchell, who tumbled to his death after a clifftop tussle.
That storyline seems positively soporific, however, when compared to last year's catalogue of carnage, which included a heart transplant, a murder attempt and a helicopter crashing in the clinic's car-park.
So what can fans look forward to in this year's instalment? Its climax - an action-packed outdoor sequence that had to be rescheduled after its West Auckland location was subject to tornado warnings - is a closely guarded secret, but I can reveal that earlier in the episode, the clinic is targeted in a drug heist that leads to a fire and the mass evacuation of the facility. And then things go really pear-shaped.
We're watching the start of the aforementioned conflagration when Magasiva arrives on set with his Magic Mike impersonation.
The scene involves Dr Josh Gallagher (Chris Tempest) and Neil Hesketh (Erroll Shand), the drug dealer Gallagher has become embroiled with. Also present (but not participating in the ensuing confrontation for reasons that will be clear when the episode airs) is clinic admission's clerk Bella Cooper (Amelia Reid).
It takes place after the chaotic evacuation, judging from the overturned trolleys, scattered boxes and artfully arranged piles of medical uniforms on the floor. The set is a temporary one, created by the placement of some flimsy, movable walls.
Because a small explosion will be followed by fire on the set, director Geoff Cawthorn spends more time talking through the mechanics of the scene with his crew than he usually might.
Indeed, due to the demanding nature of the episode as a whole, it will take the equivalent of eight days to shoot it all, whereas it's the norm for the South Pacific Pictures' production line to knock out a standard 30-minute episode every working day, 48 weeks of the year.
It's a tribute to the discipline on-set that the shoot is so short. Cawthorn, the most experienced Shortland Street director currently on the roster with close to 600 episodes under his belt, runs a tight ship and all 25 crew members go about their tasks with methodical efficiency.
"Let's do the explosion in a wide-shot first," Cawthorn says to the operators of the three cameras that will simultaneously capture the action from different angles.
The scene is rehearsed several times and Cawthorn makes slight adjustments after watching the run-throughs on TV monitors tucked just around a corner from the set.
"Let's get Amelia closer to the flame," he says at one point, prompting Reid to quip, "If my face gets burned, Shortland Street will pay for the rest of my career, right?"
On hand to ensure there's no chance of that is Brendan Durey from specialist company Film Effects. He briefs everyone about what will happen, which includes the use of a six-foot high fireball pyrotechnic - "The detonation will involve a bit of a bang, so put your fingers in your ears or use the earplugs if you need your hands free" - and ensures there's a clear passage through to the exits should anything go awry and a real evacuation is required.
Those without spare digits to stick in their ears are issued with plugs (the actors are given silicone ones that aren't visible on screen) and smoke machines are activated.
It seems Dr Gallagher has received a bit of a beating, and there's an issue with the blood on Tempest's shirt not matching an earlier shot. It's replaced and his makeup retouched.
After another check for safety, as well as camera angles and focus, "rolling" is called and the sequence is shot. Then again. And again from other angles. In one take, Tempest lurches back in feigned alarm at the explosion, causing the wall to move. Another take.
When Cawthorn is finally happy he has what the editors need to cut together the scene, he makes the call to move on. The next scenes involve two characters trapped in the clinic lift while the building burns around them, heating up the lift's interior and forcing them to shed most of their clothes.
"Obviously we've chosen our most athletic actors for that," I'm told.
Enter Magasiva and Kerry-Lee Dewing, who plays nurse Kylie Brown. They rehearse their scenes of escalating panic. Magasiva is all business now, focused and intense: "If we stay in here we're going to die!"
Before shooting, makeup descends on the actors, dabbing them with soot and spraying them with fake sweat. There's no fuss, no muss. It's just another day at the office, even if the workplace is on fire.
"And rolling..."
Shortland Street's annual 90-minute episode screens tomorrow, 7pm, on TV2.
