Shawn doesn't get any farther with Lacey, either. Before she can answer his question about her dad's finances, she's distracted when they arrive at the cooler with the bouquets locked inside. She points hers out and, being the compulsive that she is, asks Shawn to break in so she can make hers better. He can't.
The day of the wedding, Shawn shows up in the bride's suite as everyone is getting ready. The maid arrives and starts to pass out the bouquets when Lacey freaks out. She needs to have her specific bouquet. She planned the wedding and has been completely uptight about everything. Shawn calms her down and she composes herself enough to perform a magic trick with her fingers for the nervous flower girl.
Shawn knows what happened! Unfortunately, he figures out the final piece in the middle of the ceremony. His only choice is to stop the wedding and reveal all in a huge psychic episode. Lacey was supposed to inherit the ring. She counted on it as her inheritance. She would have taken it sooner, but since sometimes engagements end, her father decided to keep the ring locked up until the wedding. So the only time Lacey could get it was at the rehearsal -- where she insisted it be used. The ring never went into the vault. She tripped the best man and then pretended to straighten the ring in the box, using her quick hands to palm it. Everyone was fooled except Manheim, who threatened to blackmail her. Their argument got rough, and he ended up dead. She would have gotten away with it but when the call came about the florist, she had no time to hide the ring, and so was forced to wrap it into her bouquet, which was locked up until the ceremony.