diff --git a/src/lib.rs b/src/lib.rs
index 7986c78..d9900ce 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -72,8 +72,10 @@ pub fn plan(start: Position, goal: Position, obstacle: Option<Position>) -> Plan
 
     if path_is_clear(&path_xy, obstacle) {
         PlanResult::Plan(path_xy)
-    } else {
+    } else if path_is_clear(&path_yx, obstacle) {
         PlanResult::Plan(path_yx)
+    } else {
+        PlanResult::NoPlan
     }
 }
 
@@ -122,7 +124,7 @@ fn walk(from: u8, dest: u8) -> Vec<u8> {
         (from..dest).map(|coordinate| coordinate + 1).collect()
     } else {
         // Descending: [from - 1, ..., dest].
-        (dest..from).collect()
+        (dest..from).rev().collect()
     }
 }
 
@@ -172,12 +174,7 @@ impl Planner {
 
     /// Replaces the inputs and forgets any previously computed result.
     pub fn reset(&mut self, start: Position, goal: Position, obstacle: Option<Position>) {
-        self.start = start;
-        self.goal = goal;
-        if obstacle.is_some() {
-            self.obstacle = obstacle;
-        }
-        self.result = PlanResult::Pending;
+        *self = Self::new(start, goal, obstacle);
     }
 
     /// Computes the plan for the current inputs.