East is close to a Rule of 20 opener, but not quite, so he passes and waits. South also passes, so West opens 1♥. North makes a Michaels Cue Bid bid of 2♥, and East cuebids 2♠ to show his limit raise in ♥. South can see the writing on the wall, so he jumps straight to 4♠ to put pressure on EW. West knows he needs to bid on, but also knows partner is a passed hand (and therefore the perfect cards for slam are a little less likely), so he chooses 5♥. That's probably enough for North and South, both of whom are probably a little concerned that they can't defend 6♥. The slam could be reached if East were to find a jump to 4♣ as a Splinter , after 2♥ from North. Now West can see that as long as East has the ♦A or ♦K, slam is very good.
As it turns out, the only way to beat 6♥ is to get North his ♦ ruff - which would be pretty easy if EW ever divulged that fit as well, but might be hard to find otherwise, although North might try the ♦ if EW reach slam.