The top-seeded Storm led Phoenix 2-0 in the semifinals and then dropped two straight road games before winning Game 5 in Seattle.
With Mystics star Elena Delle Donne appearing to get stronger with each passing day, the Storm can't afford to give away any games.
"We can't relax," Storm forward Natasha Howard told the Seattle Times. "Not now. We know they're going home and they'll feel good about being at home in front of their fans. But we can't take our foot off the pedal. That got us before. We went through that and now I think we'll handle it much better."
Home has been an evolving term for the Mystics of late. With Capital One Arena unavailable, the Mystics played their semifinal home games at the Smith Center on the George Washington University campus. With that facility no longer an option, they'll be hosting the Storm at EagleBank Arena on the George Mason campus in Fairfax, Va.
Seattle is in the WNBA Finals for the third time in franchise history. They won the championship in their first two appearances in 2004 and 2010. They're on the verge of becoming the sixth franchise in league history to win at least three championships.
To win the first championship in franchise history, the third-seeded Mystics must win three straight games, something no WNBA team has done in the best-of-five Finals.
Converting their 3-point attempts would be a big step in the right direction.
In Game 1, Washington made just 3 of 21 shots from beyond the arc. In Game 2 they were 0-for-16, though they forced 15 turnovers and were in the game until the end losing 75-73.
"We don't make 3s, it's hard for us," Mystics coach Mike Thibault told EPSN.com after Game 2. "We're one of the best 3-point shooting teams in the league. ... It's tough when we don't make any. We rely on that, and we didn't make them tonight."
Both teams rely heavily on the 3-point shot. Seattle led the league by scoring 31.1 percent of their points from beyond the arc, with Washington next at 29.8 percent.
After scoring 10 points of 4-for-11 shooting in Game 1, Delle Donne - who suffered a bone bruise in her left knee in the semifinals -- scored 17 points on 7 of-16 shooting in Game 2 while switching from a brace to a sleeve. However, she was scoreless in the fourth quarter.
"Obviously it's really frustrating to not come away with the win, but we were able to see a lot of things," Delle Donne told the Washington Post. "And we get to build on it for these next three games."
Meanwhile, league MVP Breanna Stewart has been nearly unstoppable, averaging 23.5 points, 5.0 rebounds, 4.0 assists and 1.5 steals in the first two games.
"To start the game (Sunday), we got second touches for Stewie in situations ... and they were paint touches," Storm coach Dan Hughes told the Seattle Times. "Those are huge. Those are huge because not only is she going to score, she's going to distribute well."