NUMBER ONE: Siamese fighting fish. Fascinating creatures. Brave, but on the whole stupid. Yes, they're stupid. Except for the occasional one such as we have here. He lets the other two fights while he waits. Waits until the survivor is so exhausted that he cannot defend himself. And then, like SPECTRE, he strikes.
The symbolism in this scene is apparent; the two fighting fish are Bond and Grant. Number One is making it clear that whomever the victor is, SPECTRE will betray them to achieve their goals, even if the winner's presumably one of their own.
NUMBER ONE: Our organization did not arrange for you to come over from the Russians just for amusement, Number Three.
In case you don't remember from Dr. No, SPECTRE's a shadowy organization with the power to manipulate world governments. Doesn't get more megalomaniacal than that.
MORZENY: His response to our training and indoctrination have been remarkable.
This choice of the word "indoctrination" suggests that Grant, viewed as a nearly unstoppable super-assassin, may actually have been brainwashed into working with SPECTRE. He was pretty good raw material—a convicted murderer and prison escapee, after all—but SPECTRE took him to another level. We bet he'd hate thinking he was manipulated.
KLEBB: Corporal, I have selected you for a most important assignment. Its purpose is to give false information to the enemy. If you complete it successfully, you will be promoted. From now on, you will do anything he says.
TANIA: And if I refuse?
KLEBB: Then you will not leave this room alive.
Tania's mission is to manipulate Bond with false information. It's hard to blame her; she's only following orders, and under pain of death. But as she starts to fall in love with Bond, it'll become harder to lie to him. Klebb's overt threats here throw Tania off the scent of the real operation. She's not working for the Russians at all.
BEY: They're Bulgarians working for the Russians. They follow us, we follow them. It's a sort of understanding we have.
It's interesting that the clandestine Cold War espionage SPECTRE and Bond are engaged in isn't the way things are handled in Istanbul, where the opposing sides seem to conduct their business in plain sight. But maybe that's to distract from the true machinations beneath the surface?
BEY: You'll like my Gypsy friends. I use them like the Russians use the Bulgars. I'm afraid it's created a blood feud between them.
In one breath, Bey calls the "gypsies" his friends, then says that he "uses" them to create a blood feud. Reminds us of how CIA agents are always referred to as "assets" in spy movies. Their only value is their use to the organization. At least they know that when they sign on.
BOND: She's leaving that to me. She'll do anything I say.
BEY: Anything! My dear James... You're not using this. It all sounds too easy. We don't even know if she's telling the truth.
At this point, it seems that Bond is still viewing Tania as a tool to manipulate in order to get the Lektor device. Where's the turning point in their relationship when Bond starts to have feelings for her? Does he ever have feelings for her? Is Bond capable of having true feelings for a woman outside of seeing her as a conquest or a means to an end?
GRANT/NASH: We were keeping you alive until you could get us the Lektor.
BOND: So you had me deliver it on a plate. That's brilliant.
Bond's accustomed to using nifty devices to achieve his goal, but this time, it turns out that he's been SPECTRE's tool to get the Lektor machine. It's an unusual feeling for Bond, being the used instead of the user, but he can appreciate an ingenious plan when he sees it. He takes it like a gentleman. You can bet that his brain is working overtime to see how he can turn the tables.