The story's not bad, but the characterization in one instance leaves something to be desired.
Memory Alpha has a summary here.
Last night, I watched Broken Link and this episode back to back, and in the process, I noticed a pretty glaring contradiction. At the end of Broken Link, there's a scene - a scene I actually like - in which Sisko offers Odo some time off to adjust to his new circumstances. What is Odo's response? He replies that he needs to work because that's all he has left. That scene makes sense to me. It's always been clear to me that Odo really enjoys his job. He's precisely the sort of person who would plunge into work to avoid his feelings.
The Odo we see in Apocalypse Rising, on the other hand, is absolutely insufferable. I'm sorry, but for almost the entire episode, I feel like jumping through the TV screen and slapping him upside the head. Luckily for my sanity, Sisko finally kicks Odo in the ass. But why, exactly, is that wake-up call needed? How did we shift from the workaholic to the brooding wuss who sits in Quark's all day staring at the bubbles in his drink? This change is never explained, and that's the one serious flaw in this script.
The rest of the story is not bad, though. It's actually pretty entertaining to watch Sisko in particular embrace his Klingon persona. But really, what else would you expect from The Sisko? He's a human who loves to bust some skulls on occasion. He and the Klingons should get along swimmingly.
This is a relatively effective way to bring the Klingon arc into the greater Dominion War arc, and the occasional humor works. Unfortunately, as I note above, the writers don't keep Odo's characterization consistent, so I can't give this script anything higher than a 7.
The performances are standard for DS9 - which means they were generally good. Brooks does chew the scenery sometimes, but I'm inclined to forgive him just this once. After all, Sisko was posing as a Klingon, and Klingons are supposed to be melodramatic.
There are no outstanding messages here. This is a pure plot-mover.
DUKAT: Major, I must say I'm shocked. You use my daughter to lure me here, you're asking me to risk my ship on some fool's errand into the Klingon Empire, and you're pregnant. I hope First Minister Shakaar appreciates what a lucky man he is.
KIRA: Shakaar's not the father.
DUKAT: Then who is?
KIRA: Chief O'Brien. (Dukat's look is absolutely priceless here.)
BASHIR: You're doing great.
KIRA: I don't feel great.
BASHIR: You're positively glowing.
KIRA: Oh, really?
BASHIR: I think so. But then, I suppose my opinion really doesn't count.
KIRA: It counts. But don't forget, this is still your fault.
BASHIR: My fault?
KIRA: You performed the transfer from Keiko to me.
BASHIR: After you volunteered.
KIRA: After you put the idea in my head.
BASHIR: After you flew the runabout into an asteroid field.
KIRA: After you insisted we check on those anomalous bio-scans.
BASHIR: That was Keiko.
KIRA: That's right, it was. But I'd rather blame you! (Ha ha on the in-joke, guys.)
WORF: We shall start with you. I'm waiting.
ODO: I don't understand.
WORF: I'm not interested in excuses! Are you a Klingon warrior or an Alverian dung beetle?
ODO: I really don't see the point
WORF: Do not look away from me! I called you a dung beetle!
ODO: I heard you.
WORF: And what is your response?
ODO: You should have your eyes examined. (Heh.)
ODO: Captain, I have no business being on this mission. I'm not a very convincing Klingon.
SISKO: Then you'd better work on becoming one. Because like it or not, you are on this mission.
ODO: I'd hate to be the reason it fails.
SISKO: Let me worry about that. Odo, I know this has been a difficult time for you. That you never would've chosen to become a solid. But what's done is done. Brooding isn't going to change anything, and shirking your responsibilities isn't going to make you feel better about yourself.
ODO: No, I don't suppose it will.
SISKO: Then I suggest you get back in there and do your job. (A necessary kick in the pants.)
DAMAR: Sir, the holofilter's not working.
DUKAT: What do you mean it's not working?
O'BRIEN: Let me take a look at it.
DAMAR: Sir, they're repeating the request.
O'BRIEN: The optronic relays are fused.
ODO: Maybe Worf should speak to them.
WORF: I might be able to convince them that --
DUKAT: I have a better idea.
(At that, Dukat fires a spread of torpedos, destroying the other ship.)
WORF: You should have let me speak to them!
SISKO: Was that really necessary?
DUKAT: It was either that or trust in Mister Worf's ability to lie. And frankly, I have more faith in my weapons. (Leave it to Dukat to rush to violence.)
O'BRIEN: I hope I remember how to set this thing up.
WORF: If that is a joke, I am not amused.
O'BRIEN: It's not easy being funny wearing these teeth. (Hee!)
BASHIR: Your father's going to be all right, Jake.
JAKE: I suppose. But sometimes I wish that he wasn't so good at his job. That way, maybe every once in a while they'd give someone else the tough assignments.
BASHIR: He goes where he's sent. It's all part of wearing the uniform, and I doubt that's ever going to change. (Yep.)
MARTOK: What are they doing? Why doesn't Sisko just shoot him?
ODO: I have a better question. Why isn't Gowron letting his bodyguards kill Worf? I'll tell you why: Klingon honor - a concept you should be very familiar with. My people, on the other hand, don't care about honor. How did you put it? There will be no honorable combat, no formal challenges. Hardly the words of a Klingon. Tell me, General, did Gowron destroy the polaron emitters or did you? (Oh, snap!)
BASHIR: Now, that's better, isn't it?
SISKO: I don't know. I could do without ridges, but I kind of miss the fangs. (He is The Sisko. Fangs would certainly help convince others not to f--- with him. :))