NORTH  Q5    K65  AKQJ9432  96  KT986  QT9  T87    AKJ87  QJ7  J87  65    T432  A5432  A432

Dealer: North    Vul: NS   MP Scoring West Pass Pass Pass Pass Pass Pass North 1 2 3N 4 5 6 East 1 Pass X Pass Pass Pass South X 3 XX 4 5 Pass

The North hand might cause a stir if opened 2 for its having 8.5 tricks.
North's 2 cuebid was a one round force and might have been anything between a 3 bid and a 4 bid, a very big hand with diamonds, or just as it appears, a hand without a spade stopper that is interested in 3N.
Would 3 instead of 2 have meant the same thing?
Would that have been instead spade shortness with game values and 4+ hearts?

South in turn cuebid 3 showing half a spade stopper and North settled into 3N briefly.
East doubled and South reviewed 'half a stopper'.
Isn't Jxx half a stopper? Surely Qxx is half a stopper.
Is Qx half a stopper? Is Jx half a stopper?
An other than clever South put the question again to North, or thought to have, with a redouble.
North's half a stopper held not its previous lustre either and a series of "ring around the rosie" sprint bidding ensued en route down 3 in a hopeless diamond slam.

Redouble at matchpoints for this partnership, at least matchpoints..."IMPs too dear?"...is an expression of doubt. Such as Txxx has been referred to as "a quarter stopper".
Surely if one hand holds 5+ spades, Txxx opposite Jx or Qx is a sure 4th round stop of such as only three of notrump.
Perhaps South should just sit back and pad up for the winter by passing 3N - the redouble could show such as Jx possibly opposite Qx, or perhaps precisely Qx opposite a North that might have stretched to show half a stopper with Jx:
"Do you have a third round spot card, partner? I don't."