Puzzle #13
Oxbow
9 × 9Intermediate10 colorsPublished October 8, 2026
Solve it in the solver Download .flow
Colors: Blue, Orange, Green, Red, Purple, Brown, Pink, Gray, Lime, Cyan.
Blue is the long color here. It zigzags out of the top-left corner, crosses the middle of the board and runs down the right edge to its dot near the bottom. Most of the board falls to forced moves from crowded dots, and the one real decision is where Red goes in the top row.
New to these puzzles? Read how to play first. Connect each pair of dots with a path, fill every cell, and don't let paths cross. This board has exactly one solution.
Hints
Hint 1: where to look
Start with Blue's two dots. Both are boxed in, one in the top-left corner and one at row 9, column 7.
Hint 2: the first idea
Keep extending every dot with only one open side, and Red's left dot ends up running right along the top row. When it reaches column 7, dropping down would cut Purple off from its partner.
Hint 3: the key step
Red runs into the top-right corner and down the right edge. Then Blue, climbing the right edge, can't turn left at row 6 without cutting itself off, so it climbs to row 4 and turns left.
Techniques used: Forced moves, Bottlenecks.
Step-by-step walkthrough
Every step below follows from the rules alone, with no guessing. Try the puzzle first and use the walkthrough when you get stuck.
Step 1 of 8
Blue's top-left dot can only go right, and each cell after that has one open side too, so Blue zigzags down to row 3, column 3. Its lower dot at row 9, column 7 is just as stuck and runs into the bottom-right corner and up the right edge. Orange's top dot steps right. Green runs down the left edge and bends around Gray's dot into column 2, while Brown's dot drops one cell.
Step 2 of 8
Brown runs right along row 4, and Blue follows one row above it to column 5. Orange's ends are now touching, so Orange connects. With Blue below it, Red's left dot can only climb into the top row, and it runs right to column 7. Pink's left dot drops into row 6 and turns right.
Step 3 of 8
The bottom-left corner fills with two paths side by side. Green continues down column 2 while Gray runs down the left edge and wraps the corner into the bottom row. Green then turns right to meet its lower dot at row 8, column 4.
Step 4 of 8
Gray finishes along the bottom row to reach its dot at row 8, column 5. Lime moves at both ends, its left dot running right along row 7 and its right dot stepping up. Blue climbs the right edge one more cell, and Pink pushes right along row 6.
Step 5 of 8
Cyan's lower dot now has only one open side. It steps up and joins its partner at row 8, column 7.
Step 6 of 8
Red's path in the top row could drop into column 7, but that would cut Purple off from its partner. Thinking ahead, Red has to run into the top-right corner and down the right edge to row 3.
Step 7 of 8
On the right edge, Blue's path at row 6 can't turn left, because that would cut it off from its own other half. It climbs to row 4 and turns left, and Red, boxed in above it, runs left along row 3 toward its lower dot. Purple closes the gap between its two dots, and Red connects at row 4, column 6. Blue's two halves keep moving toward each other, one down column 7 and the other down column 5 and right.
Step 8 of 8
The last moves are all forced. Brown's ends already touch, Blue's two halves meet in row 5, and Pink fills row 6 to reach its dot at row 5, column 8. Lime takes the final cell in row 7.