Oh, this is going to be a fun day.

The alpha shift officers already have a self-defence session scheduled for mid-morning that the MACOs have been 'invited' to attend in order to give us the benefit of their experience. This was the captain's idea, and I agreed to it, even if I didn't knock anyone over in my transports of enthusiasm. We've all been sparring partners since day one, and to a certain degree it gets stale; there's only so much variety of opposition, and it's all too easy to get complacent and stop putting in the effort because you learn what each partner will do and how to deal with it with the minimum expenditure of energy.

So in that respect I understand why, despite exhibiting a certain amount of nerves (in view of the size of most of their new opponents, entirely understandable), my fellow officers seem more excited than anything else by the prospect of trying out against strange opposition.

As their teacher, I'm glad they feel enough confidence to regard it as an adventure as they assemble in the gym where the training mats are laid out ready. I just wish that I didn't detect an air of smirking complacency among the waiting MACOs. It gives me a sinking feeling in my stomach that has nothing to do with indigestion.

I've never skimped on self-defence training. More than probably anyone else on board, I know the value of it. But these are Starfleet officers, experts in their own fields – not one of which includes knocking eight bells out of some muscle-bound oaf who could run up twenty flights of stairs with a loaded supermarket trolley under each arm and still not be out of breath.

I know T'Pol can take on any of the MACOs and wipe the floor with them. I don't have to worry about her, at least. Out of the rest, Travis is the one I know will make the best showing. The others are average to good, but he's very good. On his day, he can give me a run for my money. So I draw a silent breath of relief when he takes on the chap I've already marked down as being the best of the opposition.

The rest are fairly well matched, considering; with resignation I see that Trip has coincidentally ended up paired with Corporal Cole, whose smile has an element of 'cat' not unconnected with 'cream'. Oh well, as long as they actually get some experience of self-defence out of all the wrestling and panting, that's as much as I ask; though if the rumours are true, our Chief Engineer is likely to put up as much resistance to the delectable Miss Cole as I would to a heaped bowl of pineapple crumble.

As jointly in charge, Hayes and I do not participate. We watch, me in silence and he calling out comments and advice; once again we are polar opposites.

My fears regarding Trip's fighting spirit are proven well-grounded almost at once. In a depressingly short space of time he hits the mat. His opponent sportingly helps him up, though I am unsure quite how entirely professional her conduct is when she takes the opportunity to slap him on the bum as she does so.

That I am not the only one to observe this little intimacy is clear the next moment when – completely against anything I could have predicted – a break in T'Pol's guard earns her the due reward of a punch that sends her to the floor. Fortunately her clearly startled opponent doesn't make the mistake of slapping her bottom as he helps her up; presumably he has a healthy desire not to have his arm ripped out of its socket for his trouble.

Travis, luckily, is doing a better job of upholding the good name of Starfleet. Even Hayes delivers due praise, and I look on with pride that I do my best to conceal as he more than holds the upper hand in his bout.

Sadly, this state of affairs doesn't last. The MACO's superior training tells, and eventually Travis hits the mat – hard. So hard, in fact, that blood is leaking from his cut lip when he stands up, though with his natural good grace he congratulates the victor on a good match.

It seems that Hayes regards this kind of injury as par for the course. I don't. As he calls a break, I call a halt, and I don't give a damn that it's bad leadership for us to be seen to disagree over a decision. For a man who only this morning claimed that all he's interested in is the success of the mission, he seems astonishingly unconcerned for the welfare of the best helmsman on board, if not one of the best in the Fleet; I'd say the best, and he probably will be one day, but right now he lacks the sheer hours of experience clocked up by test pilots like Captain Archer and his old sparring partner Commander Robinson. Captain Archer, however, has far too much responsibility to be considered in the light of a helmsman, and so Travis is an irreplaceable asset whom I for one am duty-bound to protect; unlike the esteemed Major, who apparently considers him in the light of a crash dummy for MACO workouts.

At least Hayes has the discipline to submit to my decision. Fortunately for them, the members of his squad don't wait for his confirmation of my orders before they file out; one flicker of an eye in his direction and I'd have had the offender doing burpees till they puked. My old PE teacher's fondness for that particular form of discipline gave me an excellent insight into how effective it is, and for all the MACOs' vaunted physical fitness I'll bet even they wouldn't cross me again once they'd done a full hour of it.

The brief exchange of views that follows as soon as the gym is empty should effectively ensure that from now on the MACOs will have regard to my opinions on the limits of a joint sparring bout rather than Hayes'. But as I walk away, reflecting grimly that later on we have the first of these bloody 'training sessions' that I was coerced into accepting, I realise that this victory of mine may well be fleeting. Tonight the advantage will lie with the opposition, and I'm in no doubt that my nemesis will take full advantage of it.

I've seen the specs for some of the hardware they've brought on board: the latest edition pulse rifles, pulled straight off the R&D boards and into the squad's hands for specialist training as soon as they were confirmed as part of the mission. Almost from the word 'go' I've intended to make time to get my hands on one, but somehow something always seemed to intervene. They've a training model they've brought along, and I can guess who'll be the first victim set up to demonstrate his incompetence with it in front of his own people who think he's a marksman.

I get into the turbo-lift, and just for a moment, safe from prying eyes, I drop my forehead against the wall and let out a sigh that seems to come from the bottom of my lungs. Hayes isn't the enemy; the Xindi are. And yet God help me, I can't seem to control my reaction to him. I have to keep fighting. I have to. Because once I weaken, once I stop, I...

Bloody little whinging coward, get a grip!

My father's voice sounds in my ears. The rough surface of a hawser slips through my hands, burning them. I know perfectly well how to handle a boat, even in a sea as rough as this, but I've slipped on the wet decking, and only a grab at the rope saved me from pitching overboard. The storm-dark sea slaps at my face, and I draw in a breath, suddenly choking and sick with terror. I'm wearing a lifejacket, but that fact doesn't even touch my consciousness. Water is underneath me, inches away. Waiting.

Failure is not an option.